I substituted gluten free butter cookies for 6 of the cupcakes because Aunt Lori is gluten free. I divided the crumbs up into thirds so 1/2 cup gluten-free butter cookie crumbs and 2 tablespoons of butter will make 6 cup cake tarts. 1 cup of gingersnap crumbs and 4 tablespoons of butter made 12 cup cake tarts.