In a large mixing bowl, combine all-purpose flour and powdered sugar, then cut in cold, unsalted butter until resembling coarse crumbs. Add an egg yolk and gently mix until it forms a soft dough. Wrap in plastic wrap and refrigerate for at least 30 minutes.

Preheat your oven to 375°F (190°C). Roll out the chilled pâte sucrée on a lightly floured surface until about ¼ inch thick. Fit the dough into a tart pan, trim excess, prick the bottom, cover with parchment, and add pie weights. Bake for about 20 minutes, or until lightly golden; let cool.

In a saucepan, heat whole milk with scraped seeds from vanilla beans until simmering. Whisk together eggs and granulated sugar in a separate bowl until pale. Slowly temper the egg mixture with the warm milk. Return to saucepan, cook over medium heat, stirring until thickened, about 5-7 minutes.

Once thickened, remove pastry cream from heat and transfer to a clean bowl. Cover with plastic wrap and refrigerate for at least 2 hours to set.

Pour the silky vanilla bean pastry cream into the baked tart shell, smoothing with a spatula. Refrigerate the assembled tart for an additional 30 minutes.

Before serving, adorn your tart with fresh berries, dust with powdered sugar, and sprinkle with toasted almonds. Slice and serve.