Good Chocolate Cake for tiers

3/4 c. butter, unsalted
2 c. dark brown sugar
2 tsp vanilla
3 eggs, room temp
1 3/4 c. flour
3/4 c. Dutch process cocoa
1 1/4 tsp baking soda
1 tsp baking powder
1 tsp salt
1 1/2 c. buttermilk, room temp
1/4 c. mayonnaise

Butter and flour 3 8" rounds. Bake at 350 until toothpick test.  Some of my kids can taste the buttermilk and think this is a little too sour tasting. I can't taste it. I'll have to look at Sally's Baking Addiction for her chocolate cake recipe. I just like this one because it is moist, but sturdy enough to stack and frost.