Homemade Baking Mix
The secret to the flakiest baked goods? The butter needs to be distributed in small pieces throughout the flour. It's much faster to stir in grated frozen butter (use the large holes of a box grater) than to cut in cold butter with a pastry blender or to use your fingers.
For a whole-wheat version, replace 2 cups of the all-purpose flour with whole-wheat flour.