In a food processor, combine the all-purpose flour, wheat flour, sugar, and salt until mixed well. Add the cold butter cubes and pulse until the mixture resembles coarse crumbs. In a separate bowl, whisk the egg yolk with the milk, then drizzle into the flour mixture. Combine until just moistened, press into a 9-inch pie pan, wrap tightly, and refrigerate for 1 hour to let the dough chill.

Preheat your oven to 400°F. In a baking dish, toss the sliced rhubarb with sugar, vanilla paste, cardamom, and ginger to evenly coat. Cover with foil and bake for 20 minutes. Remove the foil, stir the mixture, and bake uncovered for another 5-10 minutes until the rhubarb is tender. Allow the compote to cool to room temperature before using.

After chilling, preheat your oven to 375°F. Line the chilled crust with parchment paper and fill it with pie weights or dried beans to prevent bubbling. Bake for 10-12 minutes until the edges are set. Remove the weights and parchment, then return to the oven for an additional 3-5 minutes, until the crust appears dry. Set aside to cool slightly.

In a blender or mixing bowl, combine sugar, yogurt, eggs, lemon zest, and freshly squeezed lemon juice. Blend until the mixture is completely smooth and creamy. Set the lemon filling aside while you prepare to assemble the pie.

Spread the cooled rhubarb compote evenly across the bottom of the pre-baked pie crust. Pour the prepared lemon filling over the rhubarb, making sure to fill just below the rim to avoid overflow during baking. Preheat the oven to 375°F again and bake the pie for 20-25 minutes, or until the edges are set but the center is slightly jiggly.

Once baked, remove the pie from the oven and allow it to cool at room temperature for 2-3 hours. After it cools, place the pie in the refrigerator to chill which improves the flavors and makes it easier to slice.

Once chilled, slice the Best Rhubarb Lemon Pie and serve each piece with a generous dollop of whipped cream on top.