To make the tart dough: In a food processor combine the almond meal, flour, confectioners' sugar and salt. Pulse several times to combine. Add the butter and egg yolk, process just until the dough comes together. Distribute the dough into the 13-by-4-inch tart pan (or 10-inch round).
Lay plastic wrap over the dough and press it into the pan so that it is an even thickness. Remove the plastic and freeze the dough until it is firm, about 20 minutes.
Preheat the oven to 350 degrees F. Cover the dough with foil and fill with pie weights or beans. This will keep the dough from slouching in the pan. Bake for 25 minutes, then remove the foil and beans, bake for an additional 5 to 10 minutes or until the crust is a light golden color. Allow to cool to room temperature.
Prepare the pastry cream: Whisk together the cornstarch and 1/4 cup of sugar. Add the egg yolks to the cornstarch and mix into a smooth paste. Set aside.
Bring the milk, remaining 1/4 cup of the sugar, vanilla bean, and salt to a gentle simmer in a medium saucepan. Slowly, and in small amounts, whisk the hot milk into the egg mixture. Once the egg mixture is warm to the touch, pour it back into the milk in the pan.
Bring the custard to a gentle boil, whisking continuously for 2 to 3 minutes. The pastry cream will thicken almost immediately, but it is important to cook the starch until it isn't grainy. When the pastry cream is done it will be smooth and glossy.
Remove from the heat and add the butter and white chocolate to the pastry cream. Allow to sit for 3 minutes, then gently whisk them together. Pour the pastry cream into a shallow container. Cover with plastic wrap, pressed directly on the surface of the cream to prevent a skin from forming. Set the container in the freezer for 15 minutes (this cools down the eggs quickly) and then refrigerate for up to a few days.
Fill the cooled tart shell with the pastry cream. Decorate the top with the berries and refrigerate until ready to serve. Dust with confectioners' sugar right before slicing and serving.