This decadent recipe makes the best rhubarb tart with a chocolate tart crust, a rhubarb compote and dark chocolate ganache filling. The components are pretty easy to make, but this tart takes a little planning as it needs to chill before serving. You can also make this with rhubarb jam instead of the homemade compote to speed up the process.
This tart is sinfully good and a welcome change from the usual rhubarb recipes with its unusual pairing of dark chocolate and rhubarb. Of course, if you don't love rhubarb, make the tart without it, replacing it with another jam or layer some homemade salted caramel on the bottom before topping it with ganache!
If you would prefer milk chocolate, try this raspberry chocolate tart, which is filled with a milk chocolate ganache and topped with fresh raspberries before serving.
Jump to:
What You Need To Make A Dark Chocolate Tart With Rhubarb
There are three major components to this chocolate dessert that you will be making: a sweet chocolate cookie crust (like a sablé dough), a dark chocolate ganache filling, and the roasted rhubarb garnish. For this recipe, you will need the following ingredients:
- butter, preferably unsalted, though salted could work here!
- icing sugar (also called powdered sugar)—icing sugar will yield a more tender crust, though granulated can work in this recipe too and yield a crust with a more sandy texture
- cocoa powder—use Dutch-processed cocoa powder for the best flavour. Natural cocoa will give the crust a more muted appearance and flavour.
- egg yolks—to help bind the dough together and make the crust a little more tender
- flour—bleached all-purpose though unbleached will work as well
- water or whole milk (3.25 % fat)—to bind the crust along with the yolk
- 70 % dark chocolate—I like to use Ocoa dark chocolate from the brand Cacao Barry. It's not as sweet as some other dark chocolate products
- whipping cream (35 % fat)—please use full-fat whipping cream
- fresh rhubarb—trim the leaves and use just the stems
- granulated sugar—to roast the rhubarb. Natural cane sugar can also work for this step
- rose water or vanilla bean paste to flavour the roasted rhubarb, optional but adds a lovely flavour to the fruit layer
Please see the recipe card for the exact ingredients and quantities.
Remember to please use good-quality chocolate for this recipe because ganache is half chocolate. Get the best type of chocolate you can with a relatively high percentage of cacao that isn't overly sweet. That will make the ganache taste so much better. I used 70 % dark chocolate from Cacao Barry. Ocoa chocolate works great in this recipe, for example!
Substitutions And Variations
The chocolate cookie crust for this rhubarb chocolate tart is similar to a pâte sucrée, but where part of the flour is replaced with cocoa powder. It's baked in a tart pan with a removable bottom. If you want an easier crust, consider making a baked graham cracker crust from graham cracker crumbs, as in this Earl Grey chocolate tart. You will have to adjust the recipe to factor the change in tart pan size.
If you prefer milk chocolate instead of dark chocolate, use the ganache from this milk chocolate ganache tart recipe made with a 41 % milk chocolate.
You can replace the rhubarb compote with rhubarb jam, either homemade or store-bought. You can also use raspberry jam if you prefer, or even caramel sauce.
How To Make A Rhubarb Ganache Tart
There are three major components to this recipe with a few steps to each. You will be making:
- chocolate tart dough that you chill, then roll out to make your tart shell, which you will blind bake
- homemade rhubarb compote to fill the tart (but you can replace this with jam!)
- dark chocolate ganache
Here's how to make this tart:
Step 1—Begin by making the chocolate tart dough by first creaming together the butter, icing sugar, and cocoa powder (image 1) before adding the egg yolk (image 2) and then the flour (image 3). Flatten the dough into a disk to chill it because it is too soft to work with at this point (image 4).
Step 2—After chilling the dough, you can roll it out between parchment paper sheets with a rolling pin (image 5). Line your tart pan with the dough and trim it to fit the pan (image 6). Dock the pastry with a fork to create air vents (image 7), then bake it until completely baked through (image 8).
Tip: To unmold the crust, check out my tips for how to remove a tart from a tart pan.
Step 3—While the dough is chilling (or when the tart is baking), make the rhubarb compote by combining the chopped rhubarb with sugar (image 9) and heating it until it boils and forms a thick compote (image 10). Let cool completely before using.
Note: you can also make the compote in the oven by roasting rhubarb with sugar, but make sure to heat it enough until the compote is thick and the water has mostly evaporated, otherwise your tart will be watery.
Step 4—Make the dark chocolate ganache when all the other components have cooled, combining chopped chocolate in a small bowl (image 1) with hot cream and emulsifying with a stick blender (image 12).
Step 5—Assemble the tart by placing the baked chocolate tart shell on your serving plate, then filling it with compote (image 13) and chocolate ganache (image 14), using a mini offset spatula to smooth it out (image 15). It doesn't have to be perfect (image 16). Chill the tart in the fridge until the filling has set.
I like to dust the tart with cocoa powder and dried rose petals to decorate it.
Tips For Perfect Dark Chocolate Ganache
Because of its high cocoa content and low sugar content, dark chocolate can be tricky to transform into ganache and to work with. Here are some tips:
- Use one type of chocolate to make ganache: What I discovered from making this tart is that, though it was very convenient to use a mixture of dark chocolates to use up the odds and ends in your cupboards, the combination of chocolates makes it more difficult to achieve a perfect ganache and the ganache may split or break if you use a mixture of chocolates.
- A 1:1 ganache is the easiest ganache to make: if this is your first ganache, make it a 50/50 ganache that is half cream, half dark chocolate, by weight. You will have an easier time melting the chocolate and emulsifying the mixture than a ganache with a higher ratio of chocolate.
- Do not overheat the cream and chocolate: if the cream is too hot, the ganache will likely split. Don't heat the cream above 80 °C and make sure it is below 80 °C when you pour it over the chocolate
- Dark chocolate with a high percentage of cacao solids and low in sugar is prone to splitting when you make ganache. This is normal. To avoid the ganache splitting, you can add 15 grams of glucose to the cream. The sugar will stabilize the ganache and help the emulsion form. This is optional but helps a lot!
Tip for what to do if your chocolate ganache breaks or separates: if you make your ganache incorrectly, you will find that as you stir it, the fats begin to separate from the creamy chocolate mixture and it just won't look right. If this happens, the emulsion of the ganache is broken, but you can fix it! Simply add a couple of tablespoons of cold milk (or even water), stir, et voilà: silky smooth chocolate ganache. It works. Trust me. This tart is proof!
Other Rhubarb Recipes
If this rhubarb tart seems like a lot of work, but you still want to bake with rhubarb, you can always make these rhubarb recipes:
- strawberry rhubarb crumble muffins
- rhubarb muffins with streusel
- rhubarb jam without pectin
- mini strawberry rhubarb crumbles
- blueberry rhubarb crisp
- rhubarb crisp
If you tried this recipe for the best rhubarb chocolate tart (or any other recipe on my website), please leave a ⭐ star rating and let me know how it went in the comments below. I love hearing from you!
📖 Recipe
Roasted Rhubarb Chocolate Tart
Ingredients
Chocolate dough
- 84 grams unsalted butter cut into small pieces
- 63 grams icing sugar
- 25 grams Cacao Barry extra brute cocoa powder
- 1 large egg yolk(s)
- 170 grams bleached all-purpose flour
- 1.25 mL Diamond Crystal fine kosher salt
- 15 mL milk
Rhubarb compote
- 225 grams fresh rhubarb washed and trimmed, and cut into 10 cm lengths
- 100 grams granulated sugar
- 15 mL rose water optional
- 5 mL vanilla bean paste
Dark chocolate ganache
- 260 grams dark chocolate (70 % cocoa content) chopped
- 250 mL whipping cream (35 % fat)
Decor
- Cacao Barry extra brute cocoa powder for dusting on the finished tart before serving
- dried rose petals for decorating the tart
Instructions
To make the chocolate dough
- Cream together the butter, icing sugar and cocoa powder until smooth and well mixed.
- Add the egg yolk and mix it in, then add the flour and salt and mix the dough to form a crumble.
- Add the milk and mix it in to bind the dough together.
- Shape the dough into a disk and wrap it in plastic wrap. Refrigerate for at least 1 hour or until firm.
- Roll out the disk of dough between two pieces of parchment until it is 3 mm thick.
- Line a 9-inch removable bottomed tart pan with the dough and work it into the corners and edges. Trim and neaten it up.
- Chill the unbaked tart for half an hour or until very, very cold.
- Preheat the oven to 350 °F (175 °C) while the tart base chills.
- Dock the pastry with a fork to allow steam to escape (make sure to cut all the way through).
- Place the tart on a baking sheet and blind bake the tart shell for about 20–25 minutes until the pastry is fully cooked and appears dry (not glossy). Watch for air bubbles forming under the pastry. If this happens, take a fork, a thin pairing knife, or even a cake tester to poke through the pastry, gently pressing it back in place. Once the crust has set, air pockets won't form anymore.
- Remove the tart from the oven. Let it cool before unmolding it carefully and placing it on a plate.
To make the rhubarb compote
- Combine the chopped rhubarb and sugar in a small saucepan and heat it over medium–high heat to melt the sugar and soften the rhubarb. When it boils, let the compote boil for several minutes to cook the rhubarb and boil off as much of the water as possible. Set aside to cool.
To make the chocolate ganache
- Heat the cream in a small saucepan until it is steaming hot (just below 80 °C or 175 °F), then pour it over the chopped chocolate.
- Wait two minutes for the heat to disperse, then begin to stir it from the middle, out, until you obtain a smooth, silky ganache. Use an electric stick blender to ensure the chocolate is all melted and the mixture well emulsified. (If all else fails, see above for my ganache saving tip in the notes!).
To assemble the tart
- Line the bottom of the baked tart shell with an even layer of the rhubarb compote.
- Top with ganache, smoothing it out from edge to edge. Let the tart set in the fridge for a couple of hours.
- When you are ready to serve the tart, dust the top with some cocoa powder to make it pretty and decorate with dried rose petals.
Notes
- This recipe calls for Diamond Crystal fine Kosher salt. If using regular table salt, add half the amount or the recipe may be too salty!
- For the dark chocolate, I used Cacao Barry Ocoa 70 % dark chocolate.
- When making dark chocolate ganache with a high percentage of cacao and low in sugar, the ganache may separate. This means the fats begin to separate from the creamy chocolate mixture. It just won't look right (might even be lumpy and greasy looking) and when you chill it, you will notice white cocoa butter drops on the surface of the ganache.
- One way to stabilize dark chocolate ganache and prevent separation is to add a little glucose (corn syrup or even honey) to the cream. Heat the cream in this recipe with 15 grams of glucose (or corn syrup or honey) to melt it in. This should help you achieve a more stable ganache that is less prone to separating.
- I like to use a stick blender (hand blender) to combine the cream and chocolate. I find my ganache doesn't break when I use the stick blender.
- Don't overheat the cream - if it's too hot, your ganache may split! Make sure it is under 80 °C before adding it to the chocolate.
- If your ganache splits or breaks, the emulsion of the ganache is broken, but you can fix it before pouring the filling in the tart shell! Add a couple of tablespoons of cold milk at a time (or even water), stir a lot and repeat this until it comes together, et voilà: silky smooth chocolate ganache!
Linda says
What would be the measurements converted to teaspoons, cups, etc. I’ve never used grams and the like.
Anonymous says
This dessert sounds phenomenal...and hope that pastry school is going better. I'm in pastry as well, and sometimes, crap happens. But it sounds like you're putting so much extra work in at home i'm sure you'll prevail.
Good luck!
Peggy G. says
I can definitely relate on the school end. But then again, you have to learn so much, it's kind of hard to cram everything in more than once? But having a second chance should always be available - so good luck on the fight! This tart sounds AMAZING, by the way =)
El says
School sounds a bit frustrating at the moment. I agree with you though-practice makes perfect. It also requires a lot of time. That said, all of the desserts I've seen from you thus far look amazing. This dessert looks especially good. Keep plugging away!
Melissa@EyesBigger says
Ah sorry to hear you're struggling. I can imagine it's horribly frustrating. But sometimes, when things are toughest that means you're coming to a turning point where things will start to click.However, this tarts looks gorgeous. Isn't chocolate and rhubarb a gorgeous combination? I wonder why more people don't give it a try? I'm definitely going to experiment with this duo more!
Rumpydog says
I'd never considered combining rhubarb with chocolate. This sounds delicious. Gotta try it!
Hester @ Alchemy in the Kitchen says
Good tip to correct a separating ganache! Love this flavour combo. Roasting really brings out the flavour in rhubarb. Can't get enough of the stuff.