Preheat your oven to 350°F (175°C). Grease and line two 8-inch round cake pans with parchment paper.

Gather mixing bowls, measuring cups, and an electric mixer for an easy baking experience.

In a medium bowl, whisk together the all-purpose flour, baking powder, baking soda, and salt until light and airy.

In a large mixing bowl, beat the unsalted butter, 1 cup of creamy peanut butter, granulated sugar, and brown sugar until light and fluffy.

Gradually add the eggs one at a time, mixing well after each addition, then incorporate the vanilla extract.

Alternate adding the dry ingredients with the milk and sour cream until just combined.

Divide the batter between prepared cake pans and bake for 28-32 minutes until a toothpick comes out clean.

Let the cakes cool in the pans for about 10 minutes, then transfer to a wire rack to cool completely.

Mix softened cream cheese and remaining peanut butter until smooth, then gradually add powdered sugar and heavy cream.

Place one cake layer on a serving plate, spread a generous layer of the filling on top, then add the second layer.

Melt semi-sweet chocolate with 1 tablespoon of heavy cream and drizzle over the assembled cake.

Sprinkle chopped peanut butter cups or chocolate chips on top of the cake if desired, then chill briefly before slicing.