Crust: Combine the butter, flour and salt in the food processor. Pulse until the mixture looks like grated Parmesan. Drizzle in half of the ice water and pulse until the mixture forms a rough ball, adding the remaining water if needed. Remove the dough from the food processor, form it into a disk, wrap in plastic and refrigerate for at least 1 hour.
Filling: Cook's Note: Enough for 2 tarts. It's easier to make a larger quantity and it will last in the refrigerator for months.)
In a small saucepan melt the butter and cook it until it starts to brown and begins to smell like hazelnuts. Transfer the butter to the bowl of a stand mixer equipped with a paddle, then add the sugar and beat together on a medium speed. Gradually add the flour. Once the flour is incorporated, add the eggs, 1 at a time. Beat in the vanilla bean seeds.
Apples: In a large saute pan over medium heat, melt the butter. Add the apples and sugar and cook until they start to soften, about 6 to 7 minutes. Pull the pan off the burner and add the brandy. Return to the fire and flambe, if desired, or just let the alcohol burn off. Toss in the raisins and reserve.
Assembly: Remove the dough from the refrigerator 15 minutes before ready to use, this will allow the dough to soften and come to room temperature.
Dust a clean work surface with flour. Roll the dough out to about 1/8-inch thickness and lay it into a 9-inch tart pan with lots of overhang on the sides. Schmear half of the filling into the bottom of the tart pan and top with the apple mixture. Fold the dough overhang over the top of the apples. Brush the dough with the egg wash. Refrigerate the other half of the filling for another use.
Bake the tart in the preheated oven until the top is golden brown and slightly crispy, about 35 to 40 minutes. Remove the tart from the oven, cut into wedges and serve.