Also, don't leave off the flaky salt on top of the frosting, that would be a mistake. Peanut butter cake is a natural with salty caramel frosting, you'll see. I used Jif Natural Creamy Peanut 🥜 Butter, no need to stir and makes a great peanut butter and jelly sandwich.
Ingredients and Recipe for Peanut Butter Cake with a Salty Caramel Frosting
Peanut Butter Cake
3/4 cup brown sugar
2 large eggs
1/2 cup creamy or smooth peanut butter
1/2 cup buttermilk
1/2 cup canola oil
1 teaspoon vanilla extract
1/2 teaspoon fine sea salt
1 & 1/4 cups all purpose flour
1 & 1/2 teaspoons baking powder
1/4 teaspoon baking soda
Salty Caramel Frosting
1/4 cup unsalted butter
1/2 cup light brown sugar
1/4 cup heavy cream
Pinch of sea salt
1/2 cup powdered sugar
Flaky sea salt, sprinkle on top of frosting
Preheat the oven to 350F
Spray a 9" cake pan with baking spray
Make the cake in the bowl of a stand mixer. Beat the brown sugar on medium until lighter in color and foamy, about 1 minute, beat in the peanut butter, mix until combined. Add the buttermilk, oil, vanilla and the salt, beat until smooth. Beat in the flour, baking powder, and baking soda until well combined.
Pour the batter into the prepared pan, tap on the counter to remove any bubbles in the batter and smooth the top with a small offset spatula. Bake the cake until puffed, golden brown and a cake tester comes away clean, 35-40 minutes. Cool on a metal rack for about 15 minutes before turning out to continue cooling.
For the frosting, melt the butter, brown sugar, cream and water over a medium heat in a saucepan. Bring the mixture to a full rolling boil and cook for about 3 minutes, turn off the heat. Let the mixture cool for 3 minutes, stir with a spatula a few times to help cool. Whisk in the salt and the powdered sugar until smooth. Immediately spread the icing over the cooled cake and sprinkle with the flaky salt. Let the frosting set up for about 20 minutes before slicing. This cake will not last but it can be refrigerated and served cold, also very good.