Preheat your oven to 350°F (175°C) while you prepare four 8-inch cake pans. Line the bottoms with parchment paper and lightly spray the sides with non-stick cooking spray.

In a large mixing bowl, sift together all-purpose flour, granulated sugar, cocoa powder, baking powder, baking soda, and fine salt.

In a separate bowl, whisk together warm water, buttermilk, vegetable oil, large eggs, and vanilla extract until well combined.

Gradually pour wet ingredients into the bowl with dry ingredients, gently folding them together until just mixed.

Divide the batter evenly among prepared cake pans and bake for 22-25 minutes or until a toothpick inserted comes out with moist crumbs.

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

In a heavy-bottomed saucepan, heat granulated sugar over medium heat, stirring gently until it melts and turns amber in color, about 5-8 minutes. Whisk in unsalted butter, heavy cream, and a pinch of salt until a smooth caramel forms.

In a mixing bowl, beat unsalted butter and creamy peanut butter together until fluffy. Gradually add vanilla extract, a pinch of salt, powdered sugar, and heavy cream, mixing until smooth.

Start layering your cooled cake by placing one layer on a serving plate. Spread a layer of peanut butter frosting followed by a drizzle of peanut caramel. Repeat with remaining layers, chilling for about 30 minutes.

In a small saucepan, gently heat heavy whipping cream until it's steaming. Pour the hot cream over milk chocolate chips in a bowl and let it sit for a couple of minutes before stirring until smooth.

Pour the chocolate ganache over the top of the chilled cake, allowing it to drip down the sides. Finish with additional peanut caramel, chopped salted peanuts, and mini Snickers bars.