Preheat your oven to 350°F (175°C). Prepare three 8-inch round cake pans by greasing and flouring them.

In a medium mixing bowl, combine the all-purpose flour, cocoa powder, baking soda, and salt. Whisk together until well-blended.

In a larger mixing bowl, use an electric mixer to beat softened unsalted butter, granulated sugar, and brown sugar until creamy and fluffy.

Add eggs one at a time, beating well after each addition.

Mix in the vanilla extract until fully combined.

Gradually alternate adding the flour mixture and buttermilk to the butter mixture, starting and ending with the flour mixture.

Stir in hot water until the batter is smooth.

Pour the batter evenly into prepared cake pans.

Place the pans in the oven and bake for 30-35 minutes. Check for doneness with a toothpick.

Let the cakes cool in the pans for about 10 minutes before transferring to wire racks to cool completely.

For the peanut butter filling, beat together creamy peanut butter, powdered sugar, and heavy cream until smooth and fluffy.

Place one cooled layer on a serving plate. Spread a generous amount of peanut butter filling on top.

Add the second layer and repeat the filling process. Finish with the third layer.

For ganache, melt chocolate chips and heavy cream together until smooth, then pour over the assembled cake.

Garnish with peanut butter chips and chopped peanuts before serving.