I mostly followed a recipe that I found on tablespoon.com to make these personal-sized cakes, but I used smaller jars and slightly different color mixtures than the ones recommended on the website. As a long-term fan of all things bright and colorful, this recipe, and my results, were very exciting to me! :) Now I just have to frost the cakes and then share them with people.
If anyone wants to try making their own, here is the recipe I used:
Two hints: they have oddly specific instructions for how to create the colors, but because I didn't have all the food dye colors that they said to use, I just improvized and they turned out fine. Also, smaller jars work much better than the Mason jars they recommend. I did four small jars and one large Mason jar, and the Mason jar didn't cook as well and turned out kind of lumpy and ugly, whereas the small jar cakes look tasty and pretty!