½cup (113g, 4 oz)unsalted butter, at room temperature
¼cup (50g)granulated sugar
1cup (120g)all purpose flour
1 ¼cups (120g)almond flour (also called almond meal)
¼cup (30g)all purpose flour
¾cup (150g)granulated sugar
1tablespoonlemon zest (zest of 1 medium lemon)
3tablespoon (45g, 1.5 oz)butter, cubed
3cups (366g, 13 oz)rhubarb, sliced on the bias (I used three large thick stalks)
¼cup (82g)strawberry jam (or another fruit jam such as apricot)
1teaspoonwater, if needed, to thin jam for brushing
¼cup (31g)powdered sugar (optional)
Into the bowl of a stand mixer fitted with the paddle attachment, add the butter, sugar and salt. Mix well to combine, and continue beating on medium high until mixture is pale and fluffy, about two minutes. Scrape down the sides of the bowl.
Add the flour and mix until just combined. It will be coarse and grainy.
Add the egg yolk and mix for about 30 seconds. The dough should start to pull together into a ball.
Flatten the dough into a disc shape and wrap well with plastic wrap. Refrigerate for at least an hour.
Remove dough from refrigerator and let sit for 20-30 minutes to soften slightly. On a lightly floured surface, roll the dough out to a 10 inch diameter circle, making sure that it does not stick. Sprinkle a bit of flour on top of the dough and work surface as needed.
Carefully transfer dough to the 9 inch tart pan by rolling it around the rolling pin and unrolling it over the tin. Gently press the dough down into the pan and up the sides, ensuring that no empty space remains between the dough and the pan. If any cracks or tears occur, patch with extra dough scraps. Trim the excess dough with a knife held parallel to your work surface to ensure the tart shell has a clean edge. Cover tart pan with plastic wrap and return to the refrigerator to chill for 30 minutes.
Preheat oven to 400 degrees F (200 C, Gas number 6). Remove tart pan from refrigerator and cover the dough with a piece of parchment paper. Fill with pie weights or dried beans (I use and reuse the latter) to keep the dough from bubbling up. Bake for 6 minutes and then carefully lift the weight-filled parchment from the pan. Return to the oven to bake an additional 6 minutes. Place on a baking rack to cool.
In the bowl of a food processor, add the almond flour, flour, sugar, lemon zest, vanilla and egg. Scatter the butter over the top.
Process until well mixed. You may need to stop the processor to scrape down the walls partway through.
Pour filling into cooled tart shell. Use an offset spatula to smooth the filling evenly around the entire shell.
Preheat oven to 350 F (177 C, Gas number 4) and place rack in the middle of the oven.
Cut the rhubarb on the bias into long thin slices. (Instead of simply cutting straight across the stalk at a 90 degree angle, turn your knife 45 degrees so that it makes a diagonal cut.) Continue cutting along same angle with remaining rhubarb. This creates longer, thinner slices.
Place the rhubarb stalks onto the frangipane filling in a decorative pattern, pressing down gently. For this tart, I used four rhubarb slices for each square to make a square basket parquet pattern, also known as parquet mosaique. If you do a Google image search for visuals of either of these terms and also look at the photos I've included here, you'll get a sense of the pattern.
As your pattern nears the edges of the tart, trim the rhubarb slices to fit the remaining space on top of the frangipane filling so that the rhubarb stays within the tart border.
Using a pastry brush, gently brush strawberry jam onto the rhubarb slices. If the jam is too thick to apply easily, add a teaspoon of water and stir well to create a thinner jam.
Bake for 45-55 minutes, or until tart edge is golden brown and frangipane filling is set and no longer moist and shiny. Set on a baking rack to cool somewhat. Immediately before serving, dust with powdered sugar (optional) by placing the powdered sugar in a small sieve and tapping it (lightly!) with your hand as you move it over the tart.
Rhubarb Frangipane Tart https://www.theflouredtable.com/rhubarb-frangipane-tart/