Step 1

Preheat the oven to 400 degrees F.

Step 2

Stir the rhubarb, sugar, vanilla bean paste, and cardamom together in a 9-inch square or round baking dish.

Step 3

Cover and bake for 20 minutes, then uncover and stir.

Step 4

Cook for about 10 minutes more to condense the juices.

Step 5

Remove from the oven and let cool to room temperature.

Step 6

Pulse the flours, sugar, and salt together in a food processor just until combined.

Step 7

Add the butter and pulse 8-10 times until the texture is pebbly with pea-size chunks of butter throughout.

Step 8

In a small bowl, whisk the egg yolk and milk together.

Step 9

With the food processor running, drizzle the milk through the feed tube until a soft dough comes together.

Step 10

Press the dough evenly with your fingers into a 9-inch pie pan, making sure the edges rise at least 1/4 inch above the rim or stretch to the edges of the lip of the pan.

Step 11

Refrigerate for at least an hour.

Step 12

Preheat the oven to 375 degrees F.

Step 13

Cover the dough with foil and fill with pie weights or dried beans.

Step 14

Bake for about 10-12 minutes, until the crust is matte, not shiny, when you peek below the foil.

Step 15

Gently lift the weighted foil off the crust and bake for 3-5 minutes more .

Step 16

Remove the crust from the oven and cool completely on a rack.

Step 17

Whisk the sugar, yogurt, eggs, lemon zest, and lemon juice together in a bowl.

Step 18

Spread the rhubarb compote in the bottom of the pie crust, then gently pour the lemon filling over the rhubarb.

Step 19

Bake the pie for 20-25 minutes, until the filling is set and starting to crack at the edges. Watch carefully to make sure the edges of the pie crust don't burn and carefully cover them with foil if they're cooking too quickly.

Step 20

Cool on a rack completely before refrigerating or slicing and serving.

Step 21

Top each slice with whipped cream, if desired.