Achieving uniform cake layers in a double-layer cake involves repeating the baking process twice and being meticulous in assembly. To double up, prepare two batches of your cake batter and microwave them separately. Once baked and cooled, the real artistry begins. To ensure your cake layers sit perfectly on top of each other, it's often necessary to shave off any uneven ends with a knife, creating a uniform shape. Next, generously spread your chosen icing or ganache on the first layer. Carefully place the other layer on top, aligning them for symmetry. Don't forget to apply icing to the top and sides as well, for a cohesive and professional look. This method not only enhances the aesthetics but also the flavor, making each bite a perfect blend of cake and icing.