Preheat your oven to 350°F (175°C), line four 8-inch cake pans with parchment paper, and lightly spray them with cooking spray.

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

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

Gradually add the dry ingredients to the wet mixture, stirring gently until just combined.

Divide the batter evenly among the prepared cake pans and bake for 22-25 minutes.

Let the cake layers cool in the pans for about 10 minutes before transferring them to wire racks.

In a saucepan over medium heat, cook granulated sugar until it melts and turns amber. Add unsalted butter, heavy cream, and salt, mixing until smooth.

In a mixing bowl, beat together unsalted butter and peanut butter until fluffy. Gradually add powdered sugar and a splash of heavy cream until spreadable.

Begin layering your cooled cake, spreading peanut butter frosting and drizzling peanut caramel between layers.

In a small saucepan, heat heavy whipping cream until simmering. Remove from heat, add chocolate chips, and stir until melted.

Drizzle remaining peanut caramel around the edges, pour ganache over the top, and decorate with salted peanuts and mini Snickers.