Sift together the flour, powdered sugar, and a pinch of salt into a large mixing bowl.

Cut the cold butter into small ½-inch cubes, then add them to the dry ingredients. Using a pastry cutter, work the butter into the flour mixture until it resembles coarse cornmeal.

Add the egg yolks and vanilla extract. Mix the ingredients together with a spatula until just combined.

Shape the dough into a ball using your hands. Divide the dough in half, as this will make it easier to roll out later. Wrap each ball in plastic wrap and chill in the refrigerator for at least an hour.

Take one ball of dough and roll it out into a round shape about ¼ inch thick. I often divide the ball in half again to make it easier to roll to an even thickness, as this portion of dough will be used for two tart crusts.

Gently drape the rolled-out dough into the tart tin and lightly press the dough into the sides. Ensure the dough fits tightly into the mold with no gaps between the dough and the tin. Be careful not to stretch the dough, as this could cause the crust to shrink during baking.

To remove any excess dough, roll over the top of the tin with the rolling pin. Then, use a fork to gently poke the bottom of the tart crust, being careful not to poke all the way through.

Repeat steps 5 through 7 with the second half of the dough in the fridge to make the other two tart crusts.

Chill the tart tins in the fridge for an additional 15 minutes. Meanwhile, preheat the oven to 375°F.

Once chilled, line the dough with aluminum foil and weigh it down with pie weights (or dry beans/rice).

Bake for 10 minutes, then remove the foil and pie weights. Continue baking for another 5 minutes, or until the crust is golden brown.

Allow the tart crusts to cool completely before filling them with ganache.

While the tarts are baking, place the blueberries in a small pot and mash them with a whisk or fork until none of the berries remain whole.

Add the heavy cream and warm the mixture over low heat. Continue to smash the blueberries until they break down completely and the mixture turns purple, which should take about 10 minutes. Turn off the heat once you start seeing bubbles forming around the edges.

In a small bowl, add the white chocolate chips. Strain the hot blueberry mixture through a mesh sieve to remove the solid blueberry bits, then whisk the remaining liquid until smooth.

Allow the ganache to cool to room temperature before pouring it into the cooled tart crusts.

Once both the crusts and ganache have cooled, carefully spoon the ganache into the crusts.

Place the assembled tarts in the freezer for at least 3 hours (or overnight) to let the ganache set before serving.