How do I get my cakes to bake flat?

It’s important to use room temperature wet ingredients. When your eggs and buttermilk are room temperature, they will better blend with the other ingredients and will be better absorbed by the dry ingredients. This all helps for your cakes to rise more evenly. Good cake pans also help. I use Fat Daddio pans. Additionally, you can use aluminum bake even strips or place a baking stone on the rack below your cakes (which helps push the air up and around the cakes like a convection oven).