Mix together the flour, skim milk powder, baking powder, salt, sugar, butter and cocoa powder (if making chocolate flavour) in a food processor.
Store mix in an air tight container or Ziploc bag in the freezer for up to 2 months.
To make the cake:
Preheat oven to 350 degrees.
Grease a 9x13 inch cake pan
Combine the eggs, water, vanilla and dry mix in a bowl. Mix well.
Pour into the greased pan.
Bake for 25 - 30 minutes.
Cool and frost as desired.
Recipe Notes
Makes enough for two 9-inch layer cakes (bake 25 - 30 minutes), or one 9X13-inch cake (bake for 25 - 30 minutes), or 24 cupcakes (bake for 18 to 20 minutes)