In a medium saucepan over medium heat, combine whole milk, heavy cream, and half of the sugar. Stir gently and let it simmer until bubbles form. In a separate bowl, whisk together the remaining sugar, cornstarch, and egg yolks until light. Gradually temper the warm milk mixture into the egg mixture, then return to the saucepan. Cook over medium heat, stirring continuously until thickened, then stir in butter and vanilla. Chill for at least 2 hours until set.

In a large mixing bowl, combine all-purpose flour, confectioners’ sugar, and salt. Cut in the unsalted butter until it resembles coarse crumbs. Add egg and vanilla, stirring until the dough comes together. Shape into a disc, wrap in plastic, and refrigerate for 1-2 hours until firm.

Preheat your oven to 400°F. Roll out the chilled dough to fit a 9-inch tart pan. Transfer the dough into the pan, press it in, and trim excess. Cover with foil, fill with weights, and bake for 10 minutes. Reduce temperature to 350°F, remove weights, prick the base, and bake for an additional 5-6 minutes until golden brown. Let it cool completely.

Spread the chilled pastry cream evenly into the cooled tart crust. Arrange an enticing mix of fresh seasonal fruits on top of the cream. Warm apricot preserves and brush it over the fruits for a glossy glaze. Serve immediately.