Preparing the Chocolate Cake

1. Preheat the oven to 350°F (175°C).
2. In a large bowl, whisk together the flour, cocoa powder, sugar, baking powder, baking soda, and salt.
3. Add eggs, milk, vegetable oil, and vanilla extract. Mix on medium speed until smooth.
4. Stir in the boiling water. The batter will become thin, which is what makes the cake moist.
5. Grease two 9-inch round cake pans and divide the batter evenly.
6. Bake for 30–35 minutes or until a toothpick comes out clean.
7. Let the cakes cool for 10 minutes, then transfer them to a wire rack to cool completely.

Making the Peanut Butter Cheesecake Filling

1. Beat the softened cream cheese until smooth.
2. Mix in the creamy peanut butter and powdered sugar until fully combined.
3. Add vanilla extract.
4. Add eggs one at a time, mixing on low speed until just combined to avoid overmixing.

Assembling the Cake

1. Place one cooled chocolate cake layer on a serving platter.
2. Spread the cheesecake filling evenly over the first layer.
3. Gently place the second chocolate cake layer on top.

Making the Ganache

1. Heat the heavy cream in a small saucepan until it begins to simmer.
2. Pour the hot cream over the chopped chocolate in a heatproof bowl.
3. Let it sit for 5 minutes, then add butter and stir until smooth and glossy.

Finishing Touches

1. Pour the ganache over the cake, letting it drip naturally down the sides.
2. Add optional toppings like chopped peanuts, chocolate shavings, or whipped cream.
3. Chill in the refrigerator for at least 1 hour before slicing to help the cake set and improve texture.