You Will Need:

2 cups powdered sugar, sifted
3 tablespoons instant nonfat milk powder
6 tablespoons butter, softened

In a medium bowl, combine powdered sugar and milk powder. Stir with a wire whisk to blend. With a pastry blender, cut in softened butter. Spoon about 1/3 cup of mixture into each of 8 small bags. Seal tightly and store refrigerated. Makes 8 packages. For chocolate frosting, add 1/2 cup unsweetened cocoa.

To use: Combine 1 package of the above mix plus 3/4 teaspoon water in a small bowl. Stir well with a spoon until smooth and creamy. Makes about 1/4 cup frosting. A drop or two of vanilla may be added if desired.

Here's another recipe for homemade Easy Bake Oven Mix.
This time, Chocolate!

Dear Aunt Brenda,

I know the holidays are over, but I want a Fruitcake recipe. Can you help....
I got some homemade fruitcake from someone in Canada, and I wanted to try and make some. Mom Shoop

Dear Aunt Brenda,

I'm looking for a cake mix recipe like you would use for an easy bake oven. My niece wants one for Christmas and the mixes are very expensive, so I thought maybe I could find a recipe and make up some homemade ones to give to her, I appreciate any help or ideas you have, thanks! Broke in Alabama

Dear Broke in Alabama,

Here is a recipe to get you started: