• Preheat oven to 350 degrees F. Grease and flour three 9x2-inch round pans. If you only have two 9-inch pans, You can use 2 pans but the bake time will be longer.
• In a large bowl, whisk together the flour and baking powder, then whisk in the salt.
• In a mixing bowl or bowl of a stand mixer fitted with a paddle, beat the butter, peanut butter and brown sugar until light and creamy. Beat in the eggs, one by one until blended, scraping sides of bowl often. Beat in the vanilla.
• Scrape the sides of the bowl again and add the flour mixture and the milk alternately in three parts, beating on lowest speed of the mixer (if using a stand mixer with paddle) or stirring by hand with a heavy duty scraper until batter is smooth (see note about mixing).
• Divide the batter between the pans and bake for about 20 minutes.
• Let cool for 10 minutes, then carefully turn from pans and let cool completely.

Make Peanut Butter Frosting

• In a large mixing bowl, beat the softened butter and peanut butter until light and creamy. Begin adding powdered sugar one cup at a time, beating until smooth and scraping the side of the bowl often. Add the cream gradually, beating and scraping bowl, until icing is light and fluffy.