01 -
Set your oven to 350°F (175°C). Coat a 9×13 inch pan with grease and a light dusting of flour.
02 -
Stir together the salt, baking powder, baking soda, and flour in a medium bowl. Keep this aside for later.
03 -
In a big bowl, use a mixer to blend the peanut butter, butter, brown sugar, and granulated sugar until it turns fluffy.
04 -
Add the eggs one at a time, beating after each addition. Mix in the vanilla extract too.
05 -
Add the dry mix to the wet mix little by little. Alternate this with the buttermilk, starting and finishing with the dry mix. Combine gently.
06 -
Pour the batter evenly into the pan you prepared earlier. Pop it into the oven for about 30-35 minutes. Check by inserting a toothpick; it should come out clean.
07 -
Let the cake sit in the pan on a wire rack until it cools all the way through.
08 -
Beat the peanut butter and butter together until smooth for the frosting. Slowly add powdered sugar, milk, and vanilla, and continue beating until it’s fluffy.
09 -
Spread the frosting across the cooled cake. Cut into pieces and enjoy.