Preheat the oven to 325 degrees F.

Butter three 8-inch round cake pans, line them with parchment paper, and butter the parchment. Dust the parchment with flour and knock out the excess flour.

In a medium bowl, mix the cocoa powder and sour cream with 1 1/4 cups hot water and set aside to cool.

In a large bowl, sift the flour, baking soda, baking powder, and salt together and set aside.

Using a standing mixer fitted with the paddle attachment, beat the butter and shortening together on a medium speed until light and fluffy, about minutes — the mixture will appear to string or ribbon throughout the bowl.

Add the sugars and beat on medium speed until light and fluffy, about 5 minutes more.

Add the eggs, one at a time, mixing about 10 to 15 seconds after each addition until the egg is incorporated into the mixture.

Then turn the mixer to low, add the vanilla, and beat until incorporated. Scrape down the sides of the bowl and mix again for 30 seconds.

Beginning with the dry ingredients, add the dry mixture and the cocoa mixture to the mixer bowl in three alternating parts, ending with dry.

Divide the batter among the prepared pans. Use an offset spatula to level the batter.

Bake the cakes from 35 to 40 minutes, rotating halfway through the baking time, until a toothpick inserted in the center comes out clean.

Transfer the pans to a wire rack and cool for 30 to 45 minutes. Turn the cakes out onto the rack and let them cool completely. Remove from parchment.

Using an electric mixer, beat the butter, peanut butter, cream cheese and salt at medium speed until smooth.

Mix in the confectioners’ sugar at low speed until fluffy.

Mix in the chocolate chips.

In a large bowl, whisk together the confectioners’ sugar and cocoa powder.

Using an electric mixer, cream the butter, cream cheese and salt at high speed until fluffy.

Mix in the cocoa-sugar mixture 1 cup at a time at low speed.

Beat in the vanilla at high speed until fluffy.

Place the chocolate, butter, and corn syrup in the top of a double boiler

Using a rubber spatula, stir the mixture until the chocolate and butter are completely melted and smooth.

Remove the pan from the heat and stir the glaze to release excess heat.

If needed, trim the cakes using a serrated knife.

Place one cake layer on a cake plate.

Spread half of the peanut butter filling over the cake layer. Place the second layer and repeat process.

Top with the final cake layer.

Frost the top and and sides with chocolate frosting. Refrigerate 15 minutes to set.

Top with glaze and peanut butter whoppers. Refrigerate to set 15 minutes before serving.

Serve at room temperature.