2. In a large bowl, mix the lemon cake mix, 1 cup of Greek yogurt, and 1 cup of water, then divide the mixture between two cake pans and bake for 15-20 minutes, until a toothpick comes out clean. Let the cakes cool for 5 minutes, then flip them onto a wire rack and cool completely.
3. Combine the strawberry cake mix, the rest of the Greek yogurt (1 cup), and a cup of water. Pour the batter evenly between two greased 9-inch round cake pans, and again, bake until the cakes pass the toothpick test. Cool for 5 minutes, then flip the cakes onto a wire rack to finish cooling.