The baking mixes that come with Easy Bake and other kid ovens normally carry peanut and tree nut allergy warnings, so we have been unable to use those. Luckily, we found a self-published book online that featured "homemade" recipes for "little oven" treats. Besides being nut allergy-friendly, making your own recipes offers your kid without all the chemicals and they're much more affordable, too. Here is one of my kids’ favorite recipes -- we tweaked it a little from the original and it works great.
Mix all ingredients together and store in an airtight bag or container.
To make a cake:
Use this same basic recipe to make yellow cake mix as well--just leave out the cocoa. I'd add a little vanilla with the wet ingredients for better flavor.