This cake wasn't very good, maybe I made it wrong, I don't know. Try it!
Swapping half the dairy milk for buttermilk introduces lactic acid, which reacts with the 2.5 teaspoons of baking powder to yield a lighter crumb. Baking at a high heat of 425 degrees Fahrenheit requires careful monitoring to prevent premature exterior browning before the center sets. Rotate the baking dish every two minutes during the 25-minute bake time to compensate for uneven oven hot spots.
Assessing baked goods visually and texturally prevents over-drying. Insert a wooden skewer into the thickest part of the center; it should emerge clean without wet batter clinging to the wood. The edges of the cake will shrink slightly away from the pan walls, and the top surface springs back firmly when pressed gently with a fingertip.