01 - Combine warm milk, instant yeast, and a spoonful of sugar in a small bowl. Let stand for 5 minutes until the mixture becomes foamy and fragrant.
02 - In a stand mixer fitted with a dough hook, combine the flour, remaining sugar, salt, eggs, and proofed yeast mixture. Knead on medium speed for 5 minutes. Gradually incorporate the softened butter, one piece at a time, and continue kneading until the dough is glossy, smooth, and elastic, approximately 10 minutes. Cover the bowl and let the dough rise in a warm spot for 1 hour, or until doubled in volume.
03 - Heat the milk in a saucepan over medium heat until steaming but not boiling. In a separate bowl, whisk the egg yolks, sugar, cornstarch, and salt together until the mixture turns pale yellow. Slowly stream the hot milk into the yolk mixture while whisking constantly to temper the eggs. Return the combined mixture to the saucepan and cook over medium heat, whisking continuously, until the custard thickens, about 3 to 5 minutes. Remove from heat, stir in the vanilla extract, and press plastic wrap directly against the surface to prevent a skin from forming. Let cool completely.
04 - Preheat the oven to 350°F. Punch down the risen dough and transfer to a lightly floured surface. Roll into a 12-inch round and place on a parchment-lined baking sheet or pizza pan. Use your fingers to press a slight raised rim around the outer edge.
05 - Spread the cooled custard evenly over the dough, leaving a 1/2-inch border around the rim. Sprinkle with 2 tablespoons of granulated sugar for caramelization and arrange fresh fruit on top if desired. Bake for 22 to 25 minutes until the crust is golden and the custard is lightly set. Cool slightly before slicing into wedges. Dust with powdered sugar just before serving.