In a food processor, combine all-purpose flour and powdered sugar. Cut in chilled unsalted butter until the mixture resembles coarse crumbs. Add the egg yolk and cold water, pulsing until the dough forms a ball. Wrap in plastic wrap and chill for 30 minutes.

Preheat your oven to 350°F (175°C).

Roll out the dough on a lightly floured surface to about 1/8-inch thickness. Cut out circles, prick with a fork, and line with parchment paper and baking weights. Bake for 15-20 minutes until golden brown, then cool completely.

In a medium saucepan, whisk together heavy cream, whole milk, granulated sugar, cornstarch, and vanilla extract. Cook over medium heat until thickened, about 5-7 minutes. Allow to cool slightly before filling tart crusts.

Fill each cooled tart shell with vanilla cream, smoothing the top. Refrigerate for at least 2 hours to let set.

Top each tart with fresh raspberries and garnish with mint leaves before serving.