Cut cold butter into small chunks and place in the freezer for ten minutes.
Mix the water and vodka together and place in the freezer for 10 minutes.
Pulse the flour, sugar, and salt until combined.
Add the cold butter and pulse until they are broken into tiny chunks.
Pulse in the water and vodka mixture until the dough just starts to come together. Cover with plastic wrap and place in the freezer for 30 minutes or in the fridge for one hour. The dough can be made up to one month in advance and frozen, or up to three days in advance when stored in the fridge.
For the apple filling and crumble topping
Preheat the oven to 375 degrees.
While the dough is resting, peel, core, and slice the apples. Drizzle a little lemon juice on top to keep from browning and cover with plastic wrap.
Roll out the dough between sheets of plastic wrap to help keep the dough intact and invert on a buttered tart pan and gently press into the bottom and sides. Remove the excess dough around the edges and puncture wholes on the bottom of the shell with a fork to allow steam to escape.
Overlap apple slices in a circular pattern in the shell.
Heat a small saucepan over medium heat and melt 3 Tbsp. butter and 3/4 cup brown sugar. Add the apple butter, bourbon, vanilla, and baking powder and simmer until thickened slightly, about two minutes.
Pour the glaze over the apples and spread evenly with a pastry brush.
For the crumble, melt the remaining butter 6 Tbsp. butter. Combine the butter, flour, 6 Tbsp. brown sugar, and oats together.
Distribute the crumble over the tart. It will not cover it completely. That is ok, we want the steam to escape.
Bake for 40-50 minutes or until the crust and crumble are golden brown.