Crumble to crumble pie

Approach

1. 1

   Put butter and sugar in a stand mixer (not a food processor), and add any flavoring (vanilla, instant coffee, cinnamon, grated citrus zest, etc.).
2. 2

   Mix the butter and sugar lightly before adding flour and any rolled oats. Mix everything into a crumbly dough. It's also possible to mix this by hand.
3. 3

   Bake the crumbs in the oven at 180 degrees for about 30 minutes. Or cover the crumbs over your desired pie filling, and bake in the oven at 180 degrees for 30-40 minutes.