Peanut Butter Cake with Chocolate Icing

Preheat oven to 350 degrees.

In a large bowl, stir together flour, sugar, and salt. Set aside.

In a small bowl, whisk together buttermilk, eggs, baking soda, and vanilla. Set aside.

In a medium saucepan, melt 1 3/4 sticks butter. Stir in peanut butter until smooth. Add boiling water, let the mixture bubble up for about 10 seconds, then remove from heat.

Pour the peanut butter mixture over the flour/sugar mixture and stir until halfway combined. Pour in the buttermilk mixture and stir gently until the batter is smooth. Pour the batter into a sheet pan or jelly roll pan and smooth the surface. Bake for 20 minutes, then remove it from the oven.

While the cake is baking, make the icing: Melt 1 3/4 sticks butter. Stir in the cocoa powder, then the milk. Remove from heat and add vanilla and powdered sugar and stir until smooth. Add more powdered sugar if you want it a little thicker.

Pour the icing over the warm cake right out of the oven and smooth the surface. Allow to sit for 10 minutes before cutting into squares and serving warm.