01 -
Set the oven to 350°F (175°C). Lightly grease a 9x13-inch pan and dust with flour.
02 -
Use a medium-sized bowl to blend together the flour, salt, baking powder, and baking soda. Keep it to the side for now.
03 -
In a bigger bowl, beat the granulated sugar, brown sugar, peanut butter, and butter until it looks fluffy and airy.
04 -
Beat one egg at a time into the mix. Stir in the vanilla extract after that.
05 -
Slowly add the dry blend to the wet mix in parts, switching with a little buttermilk in between. Start and finish with the dry mix and stir until it's just mixed together.
06 -
Pour your batter into the prepared pan and smooth it out. Let it bake for 30–35 minutes or until a toothpick comes out clean.
07 -
Let the cake sit in the pan and cool down fully on a cooling rack.
08 -
Blend the peanut butter and butter until silky. Slowly add powdered sugar, milk, and vanilla extract while beating it into a smooth and fluffy texture.
09 -
Carefully spread the frosting over the cooled cake. Cut slices and enjoy!