Preheat your oven to 350°F (175°C) and grease a 9-inch round cake pan.

In a large bowl, cream together the peanut butter, granulated sugar, brown sugar, and butter until smooth.

Beat in the eggs one at a time, followed by the vanilla extract.

In another bowl, whisk together the flour, baking powder, baking soda, and salt.

Gradually mix the dry ingredients into the wet mixture, alternating with the milk.

Pour the batter into the prepared cake pan, smoothing the top.

Bake in the preheated oven for 30-35 minutes, or until a toothpick inserted comes out clean.

Allow the cake to cool in the pan for 10 minutes before transferring it to a wire rack to cool completely.

Prepare your favorite frosting while the cake cools.

Once cooled, frost the cake and decorate as desired.