Rustic French Rhubarb Tart

Name: Rustic French Rhubarb Tart
Prep time: 30 min
Cook time: 30 min
Ingredients: ½ cup room-temperature unsalted butter; ¾ cup powdered sugar; 2 ½ tablespoons almond flour; 1 free-range egg; 2 cups all-purpose flour; ¼ teaspoon fine sea salt; 28 ounces rhubarb stalks; 2 tablespoons cane sugar ((plus 1 tablespoon to sprinkle on top)); 1 teaspoon vanilla bean paste (); 3 tablespoons almond flour; 2 tablespoons salted butter (melted)

Sweet, tangy, and buttery, this Rhubarb Tart has it all! Featuring a crumbly shortbread crust (known as “pâte sablée” in French), this tart is generously filled with a rich rhubarb vanilla filling over a bed of almond flour and topped with a glaze of melted salted butter. Perfect for a taste of summer in true French style!

rustic french rhubarb tart with a slice cut off.

Table of Contents

Why you should try this recipe

Easy – No tart pan required to make this rhubarb tart! Just make and roll the crust, add the rhubarb filling on top, and fold the edges. That’s it! For more easy French recipes, check out my French Apple Cake or, French Rice Pudding “Riz Au Lait”, Chocolate Pound Cake with Glaçage Rocher!
It has a layer of almond flour underneath the rhubarb filling, it mimics the taste of frangipane without the extra step of making it (the same technique I used in my Rustic Plum Tart).
It comes with a shortbread crust, or as the French say, “pâte sablée“. It’s crumbly, buttery, and super crunchy—like a delicious shortbread cookie! The BEST tarte base, in my opinion.

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Rhubarb Tart Ingredients

**For the shortbread crust (pâte sablée)**

flour, butter, almond flour powdered sugar, salt and egg on a marble surface.

Unsalted butter – Opt for cultured butter to achieve a rich, buttery taste, crucial for authentic French flavor. Using unsalted butter lets you control exactly how much salt goes into the dough.
Powdered sugar – is crucial for achieving the characteristic crumbly texture of the rhubarb tart crust. Substituting it with another type of sugar will result in a less friable, less shortbread-like texture.

For the rhubarb filling

rhubarb, cane sugar, vanilla bean paste, almond flour, salted butter on a marble surface.

Cane sugar – is commonly used in French pastry and imparts a subtle caramel-like flavor. It can easily be substituted with brown sugar, light brown sugar, or granulated sugar. Don’t know how to use the rest of the cane sugar, give these Brown Butter Chocolate Chip Pecan Cookies or Lemon Ricotta Cake a try!
Vanilla bean paste – I like it because it has a bold vanilla flavor and is great for coating the rhubarb pieces. You can also use vanilla powder or vanilla extract as a substitute.
Salted butter – drizzling melted butter over the rhubarb before baking enriches the flavor with a rich, buttery taste. Plus, the salt amps up the taste and balances out the sweetness perfectly. It makes such a difference!

(Note: the full ingredients list, including measurements, is provided in the recipe card at the end of the post.)

Have leftover rhubarb? Use it in my decadently buttery Rhubarb Crisp!

How to make Rhubarb Tart?

(Note: please see the recipe card below for the complete written instructions and measurements.)

mixing shortbread curst dough in a stand mixer.

Step 1. Make the shortbread crust (pâte sablée) dough. Add room-temperature butter, powdered sugar, almond flour, egg, all-purpose flour, and fine sea salt to the bowl of a stand mixer fitted with the paddle attachment. Mix until the mixture is well combined and resembles wet sand (Images 1 & 2).

Note: Alternatively, you can use a large mixing bowl and mix with a spatula.

shaping shortbread crust dough and placing it between two parchment paper sheets.

Step 2. Transfer the dough onto a 16×16-inch (40×40 cm) sheet of parchment paper. Then, shape it into a round form using the palm of your hand. Cover with another sheet of parchment paper (Images 3 & 4).

rolling shortbread crust in between two parchment paper sheets.

Step 3. Roll the dough. Using a rolling pin, roll the dough into a 14-inch (35 cm) circle (Image 5). Place the dough on a sheet pan and let it firm up in the fridge for 45 minutes (Image 6).

Note: the dough is far too soft to be rolled out as is. This is where parchment paper comes in handy!

Step 4. Meanwhile, prepare the rhubarb filling. Thoroughly rinse the rhubarb stalks under cold water and pat them dry. Trim the end and cut into ½-inch (1.5 cm) pieces (Images 7 & 8).

Step 5. Mix the filling. Add the rhubarb pieces, cane sugar, vanilla bean paste in a mixing bowl and mix well (Image 9). Set aside. Then, melt the salted butter and set aside (Image 10).

Note: You might need to reheat the melted butter before brushing it on the rhubarb.

sprinkling almond flour on top of raw shortbread crust.

Step 6. Assemble the tart. Preheat the oven to 390°F (200°C). Take the rolled crust out of the fridge (leave it on the sheet pan), and carefully remove the top parchment paper sheet (Image 11). Immediately sprinkle with almond flour, leaving a 1-inch (2.5 cm) border to fold the crust over (Image 12).

Note: The crust will seem too hard, but this is normal. It will soften quickly, so the following steps must be done immediately (if the crust softens too much, it will become difficult to fold over).

process of filling a tart with rhubarb and brushing melted butter on top.

Step 7. Add the rhubarb filling on top of the almond flour (Image 13). Then brush it with melted salted butter (Image 14).

process of folding the crust over the rhubarb filling.

Step 8. Gently fold the edges over the filling (Image 15). Then sprinkle both the crust and filling with cane sugar (Image 16). Bake the rhubarb tart in the oven for 30 minutes, until the crust is golden and the rhubarb lightly charred.

Nim Keys – Useful Rhubarb Tart Tips

Room-temperature butter – For the best texture in your shortbread crust, make sure your butter is at room temperature. The technique I like best is to cut it into small cubes and let it sit out for about 30 minutes. If you’re in a hurry, you can microwave the butter cubes on the Defrost setting (30%) in 10-second bursts until they’re soft.
The shortbread crust dough is really soft and can’t be shaped as is. This is normal and what gives the crust its deliciously crumbly texture.
The easiest way to handle shortbread crust dough is to roll it out between two sheets of parchment paper and then chill it in the fridge. Some recipes suggest putting the dough in the fridge first and then rolling it out, but from my experience, that makes the dough way too hard and rolling it becomes a real hassle!
Once the chilled dough is out of the fridge, act quickly and begin adding the toppings immediately. The dough warms up fast and becomes difficult to handle if it gets too warm.

a slice of rustic french rhubarb tart with a dollop of cream on top.

Recipe FAQs

Should I peel the rhubarb stalks?

Only if the stalks are very large with a thick skin, as those can taste rubbery. Otherwise, I don’t bother peeling them because it’s time-consuming and doesn’t make much of a difference in taste.

How to reduce the tartness of the rhubarb in rhubarb tart?

I find that using cane sugar or brown sugar along with vanilla really softens the tartness of the rhubarb and gives the tart a nice, rounded flavor.

My shortbread crust breaks and I cannot fold it over the edges. What went wrong?

The crust probably isn’t cold enough yet. It needs to be chilled to handle, and it’ll warm up fast. When folding the crust over the filling, be quick and gentle. You can slide a blade under the crust to help release it from the parchment paper.

Can I use frozen rhubarb to make rhubarb tart?

Yes and no need to thaw it. Simply combine the frozen rhubarb pieces with sugar and vanilla, then proceed with the recipe as instructed.