Combine thoroughly flour, sugar, cocoa, baking powder, and salt in a large bowl. An electric mixer on slow speed can be used for mixing. ) Add butter Or solid margarine; cut in with a pastry blender or with hands until mixture resembles coarse cornmeal. Store in an airtight container in refrigerator. Note: After refrigeration, measure amount of mix needed; bring to room temperature for easier blending. Yield: Approximately 11 cups