Preheat oven at 350°F. Grease 4, 6-inch cake pans.
In a large bowl, whisk together all the dry ingredients.
In a mixer with a paddle attachment, beat the butter and brown sugar together until light and fluffy. Add the eggs, 1 at a time and mix until well incorporated.
Add in the dry ingredients and start mixing on slow. Gradually add the milk and sour cream/Greek yogurt.
Divide batter evenly into 4 cake pans. I used an ice cream scoop to make sure each pan had equal amounts of batter. You can also you a scale to do this.
Bake for 28-30 minutes until the cake springs back when you press the top gently. Let cakes cool before removing them from pan.