If you want a lemon jello cake, use a lemon-flavored jello, with lemon pudding mix and lemon cake mix. The preparation method is same as given in the earlier recipe. Bake the cake, poke holes, pour the jello, refrigerate, apply the topping, and serve. If you want a jello pudding cake, you can use pudding as topping. Otherwise, whipped cream will be sufficient for topping. You may also go for jello cake decorations like candy sprinkles.