1 1/2 sticks (3/4 c.) butter
1/4 c. creamy peanut butter
4 eggs
1/2 c. buttermilk
2 c. sugar
3 tsp. baking powder
3 c. plain (all-purpose) flour
1 tsp. vanilla
1/2 c. water

Grease and flour 10-inch tube pan or bundt pan. Preheat oven to 350 degrees. Mix all ingredients (peanut butter and butter must be soft) and beat all slow speed 30 seconds, then at medium for 2 minutes. Pour into pan and bake for 45 minutes, then reduce to 325 degrees for 20 minutes longer. Cool completely before frosting.