Peanut Butter Cake makes a perfect cake for the peanut butter lover. This makes a great sheet cake topped with chocolate frosting or peanut butter icing.
Preheat oven to 350º F. Prepare 18x13 rimmed baking sheet pan by brushing with homemade cake release (cake goop) or by buttering and lightly flouring the pan, ensuring that the pan is well-coated and discarding any excess flour.
Add butter, water, and peanut butter to a medium-size saucepan over medium heat. Stirring frequently, bring to a boil. Remove from heat. Whisk in flour, sugar, salt and baking soda until just combined. Add in eggs, vanilla and buttermilk. Pour into prepared sheet pan and bake 20 minutes, or until the cake springs back to the touch and a toothpick when inserted into the center comes out clean. You can follow my tips for how to tell when your cake is done.