This cake has a vanilla and chocolate flavour, but there are many other flavours you could combine to make a marbled cake! Instead of using just Vanilla in the second batter like here, you could also add some Orange Zest or Coffee Extract - both will be delicious with the Chocolate! Or go for more original flavour combos like Chocolate and Strawberry, Berry and Vanilla, Chocolate and Peanut Butter, Banana and Chocolate,... I mean, as long as you have two cake batters, it is super easy to combine them into a marble loaf!