I found this recipe for Children's Easy Bake Oven.

CHILDREN'S WHITE FROSTING MIX

2 cups powdered sugar, sifted
3 tablespoons instant nonfat milk powder
6 tablespoons vegetable shortening

In a medium bowl, combine icing sugar and milk powder. Stir with a wire whisk to blend. With a pastry blender, cut in shortening.

Spoon about 1/3 cup mixture into each of 8 small containers or ziplock bags. Seal bags tightly. Label with date and contents. Store in a cool dry place. Use within 12 weeks.

Makes 8 packages of Children's White Frosting Mix.

To Use:
1 pkg. Children's White Frosting mix 3/4 teaspoon water

In a small bowl, combine mix and water. 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.