Divide the butter into two parts, 6 TBS and 3 TBS. Cut each part into 3/4" cubes. Refrigerate the larger amount and freeze the smaller amount for a minimum of 30 minutes.
Sift together the flour, salt, and baking powder and place it in the freezer for about 30 minutes.
Remove flour and butter from the freezer and refrigerator and have the ice water and apple cider vinegar ready to use.
Place the flour mixture in a food processor and pulse for about 5 seconds.
Add the larger amount of butter and pulse for about 10-15 seconds. The butter should resemble a coarse meal.
Add the smaller amount of butter and pulse until the butter is the size of large peas.
Drizzle in the water and apple cider vinegar and pulse for about 5-10 seconds, until the butter is the size of small peas.
Place the dough on a clean flat surface and using your hands bring the dough together by pressing it (DO NOT KNEAD!) into a disk.
If you would like to bake a lattice pie, divide the dough into 2/3 and 1/3 and wrap it in plastic wrap.
Let rest in the refrigerator for a minimum of 1 hour or overnight preferably.