You will have best results using spelt flour, sprouted or not, by using recipes that call for spelt flour. Rose’s recipes should be followed fairly closely to achieve the desired results, so use the flour she specifies. I do have great results using sifted whole wheat flour instead of cake flour in her recipes, but this change works because both are wheat. Spelt is lower in gluten and needs special consideration, and usually other ingredients, to make it work in baking. I suggest you use a search engine to find cupcake recipes that call for spelt flour. Good luck! Let us know if you find a good spelt recipe.