combine all dry ingredients in a mixing bowl. using your hands or the lowest speed of your mixer with paddle, slowly massage in the butter to the dry mixture (this is called 'sablaging' or the sandy method as the final result will feel like damp sand. i find using your hands works best.) until all is incorporated. take care to not allow the mixture to warm up much.
beat eggs in a bowl until fluid. stir in your flour+butter mixture until dough forms a rough ball. form into a 3-inch thick disc. wrap in plastic wrap and refrigerate until firm (1 hour).
preheat oven to 350 degrees. fill your crust with baking beans (this is to weigh the bottom down so it cooks in the shape desired. otherwise, this dough will puff unevenly). bake for 35 minutes or until crust is dry and golden brown. rotate at least once and watch for hotspots! allow to cool fully before filling.
vanilla pastry cream and topping
add milk, vanilla bean, and half of the cornstarch to a saucepan and bring to a simmer. add remaining half of cornstarch to sugar.
in a mixing bowl, beat eggs until fluid. add sugar and fully incorporate.
once milk is at a simmer, remove from heat and, while whisking, add 1/4 of the milk to the egg/sugar mixture. do this gently and be sure to constantly whisk to ensure that the eggs temper and do not scramble. add another 1/4 of the milk and repeat. continue until egg mixture is at the same temperature as remaining milk.
return entire mixture to saucepan over heat. stir constantly (i prefer using a rubber spatula to scrape the bottom) until one bubble is released. remove from heat. strain.
spread on a silpat or parchment paper and press plastic wrap over to prevent a film from forming on top. chill for one hour. once crust is fully cooled, fill a pastry bag with cream and cut the tip off. pipe cream evenly into crust.
press berries in a circular formation into pie filling. warm the nappage until liquid in a saucepan. using a brush (preferably silicone), gently wash the top of the tart with the mixture and allow to set.