My soon-to-be 5 year old son wants a lemonade cake for his birthday. Am going to decorate for a Star Wars/Indiana Jones lego theme, but need ideas for frosting and/or filling.

Help!

I've never done a lemonade cake, but my mom makes these to die for lemonade bar things. it has a lemon cream cheese frosting and filling.

Just a hint of lemon so it's not too overpowering. You could try adding a bit of lemon flavoring to a creamcheese frosting or to a buttercream.

I'm not at all sure if this will work for you, but I've made this pink lemonade cake and it's WONDERFUL. I think you could easily use regular lemonade powder to keep it from being pink. Perhaps you could use it for the cake and the filling and then decorate with your own icing? Pardon the recipe instructions, they are "for dummies" not for those with caking knowledge!

Ingredients
Cake:
Butter for coating pan
1 box white cake mix (18.25-ounce)
3 tablespoons pink lemonade drink powder
3 eggs
1/3 cup vegetable oil
1 teaspoon finely grated lemon zest

Frosting:
1 pound confectioners' (powder) sugar
1/2 cup unsalted butter (1 stick), softened
3 tablespoons frozen pink lemonade concentrate
1 teaspoon vanilla
1 teaspoon lemon zest, finely grated

Cooking Directions
Preheat the oven to 350F. Butter two 8-inch round cake pans and line the bottom with parchment or waxed paper; set aside.

For the cake, in a large bowl, stir together the cake mix and lemonade powder. Prepare the cake batter according to the package directions, using the eggs and the oil. Stir the lemon zest into the batter. Pour the batter evenly into the prepared pans. Bake for 30 to 35 minutes or until golden and a toothpick inserted in the centers of the cakes comes out clean. Let the cakes cool in the pans for 10 minuets. Carefully turn cakes out onto a wire rack to cool completely.

For the frosting, beat together the confectioners' sugar and butter until fluffy. Beat in the remaining ingredients until combined.

Transfer one cake to a cake stand or large platter. Using an offset spatula spread the top of the cake with a layer of frosting. Place the second cake on top of the first. Spread the remaining frosting over the top and sides of both layers.