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

In a large mixing bowl, sift together the flour, cocoa powder, baking powder, baking soda, and salt.

In another bowl, whisk together the granulated sugar, brown sugar, vegetable oil, eggs, buttermilk, and vanilla extract until smooth.

Gradually add the dry ingredients into the wet mixture, stirring until well combined. Then, slowly pour in the hot water and mix until the batter is smooth. The batter will be thin, but that’s normal.

Divide the batter evenly between the prepared cake pans and bake for 30-35 minutes, or until a toothpick inserted into the center comes out clean.

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

While the cakes are cooling, prepare the peanut butter frosting: In a bowl, beat the creamy peanut butter, powdered sugar, milk, and vanilla extract until light and fluffy.

For the chocolate ganache, heat the heavy cream in a small saucepan until just simmering. Pour it over the dark chocolate chips in a heatproof bowl and let sit for 1-2 minutes. Stir until smooth and glossy.

Once the cakes are cool, spread the peanut butter frosting evenly over the top of one cake layer. Place the second cake layer on top and frost the top and sides of the cake with the remaining peanut butter frosting.

Drizzle the chocolate ganache over the top of the cake, letting some drip down the sides for a decorative effect.

Warm the salted caramel sauce slightly in the microwave or on the stovetop until pourable, then drizzle it generously over the cake.

Optional: Sprinkle crushed salted peanuts on top for added texture and flavor.

Refrigerate the cake for 30 minutes to set the frosting and ganache, then serve and enjoy!