1 (18 ounce) package yellow cake mix
1 (3 ounce) package instant chocolate pudding mix
2 (3 ounce) packages instant chocolate pudding
Prepare and bake cake using the instructions at the box. Bake and cool cake according to package directions.
To make the vanilla pudding mix, mix together 1/2 cup reserved lemon juice, 1/4 cup lemon zest, 1/4 cup vanilla extract and 2 cups flour. Spread into a 9 inch springform pan.
To make the chocolate pudding mix, combine pudding mix and lemon extract. Pour mixture into prepared pan. Bake and cool according to package directions, using a knife or electric mixer. Refrigerate before serving.