Preheat the oven to 350 degrees F and grease two 6-inch cake pans very well on the bottom and sides with nonstick spray. (I use classic Pam spray.)
Add the ingredients to a medium bowl and whisk gently to combine. Divide the batter between the prepared pans, using about 1 cup and 2 tablespoons in each pan.
Bake for 18-20 minutes or until the middle is firm to a light touch and a cake tester inserted into the center comes out cleanly. Try not to overbake.
Let cool on a wire rack for 5 minutes, then carefully remove the cakes from the pans by running a paring knife around the edges to loosen. Working with one pan at a time, carefully turn the pan over onto a wire rack. The cakes should slide out easily. Let cool completely on the wire rack.
To frost, place one cake onto a cake plate or plate. Add 1/3 of the frosting to the top of the cake. Spread to the edges. Top with the second layer and the remaining frosting, then spread over the top and the sides. Add sprinkles if desired.
You can make the cakes the day before you plan to serve. Let cool fully, then place on two separate plates and wrap well with plastic wrap. Store at room temperature. Frost before serving if possible.
To make this in a 9-inch cake pan, use just one pan and bake for 24-26 minutes or until a cake tester inserted in the center comes out cleanly. Be sure to grease the pan well to ensure it doesn't stick.
If you are at all worried about your cakes sticking to the pans, (these 6-inch pans do not tend to stick, but I can't speak for every other cake pan) trace the pans onto parchment paper. Cut out the rounds, trimming slightly so they fit inside of the cakes. Place each round of parchment paper into the cake pan, then spray the paper and sides of the pan with nonstick spray. Proceed with the recipe.