Hi Mayan! You can most certainly make this cake bigger! For 12 servings, you have two options - I would say you can keep the same ingredient proportions and just bake the cake in two 8" pans for a wider cake (so shorter slices). The other thing I would suggest is making the cake x1.5 and splitting it between three 8" pans so its bigger and taller! I think either option would work well. You are welcome to double the recipe but that would end up being four 8" cakes which might be too much for what you're wanting!