Preheat oven to 325°F. Generously oil two cake pans (see notes for size variations) and line bottom of pans with parchment paper.
In the bowl of a stand mixer, mix eggs, melted butter or oil, and water for 30 seconds on medium speed. Add mix, then beat for 60 seconds on medium speed, scraping down the sides of bowl with a spatula. Divide batter evenly between pans and smooth tops with a spatula.
Place pans 3 inches apart on the middle rack of the oven. Refer to the size and shape options for appropriate baking times and bake until a toothpick inserted into the center comes out clean. Cool cakes in pans on a wire rack for 15 minutes. Run a sharp knife around edges to loosen cakes, then invert onto separate plates to cool completely before frosting.
Makes 16 servings/slices.
