The yellow layer is this
1 of those larger cartons of extra heavy whipping cream, it was close to 2 cups of it.
about 3/4 cup of lemmon juice
1 box instant vanilla pudding (although I should have used lemon maybe)
2 cups powdered sugar
Whip the cream WITH the pudding until it is firm, add the lemon, if you want to color it add that too and whip more. Slowly add 2 cups powdered sugar and whip till it's all mixed in. Stick it in the fridge.
1 can of Betty Crocker whipped fluffy white frosting
the juice from two limes and as much of the zest as I could get off of one of them.
green food color
Stir up the frosting, I had to put it in a seperate bowl. Add the other stuff, stir more. Refridgerate. When the cakes are cool top with the yellow, then the green. The yellow is really creamy. It does taste like lemon, but it's not tart at all. The green is also creamy, but really tart. It's not to where you can't just eat it, I managed to lick the spoon, but it's definately puckery. With the creamy layer and the cake though it is just perfect!
The whole recipe is an alteration of this one: http://www.bettycrocker.com/recipes/recipe.aspx?recipeId=41439