Preheat your oven to 350°F (175°C) and grease plus line two 9-inch round cake pans.

In a large bowl, whisk together the flour, sugar, cocoa powder, baking soda, baking powder, and salt until well mixed.

In a separate bowl, combine the milk, oil, vanilla extract, and eggs; whisk until blended smoothly.

Pour the wet mixture into the dry ingredients. Stir until just combined, then gradually add the hot water. Mix until the batter is smooth.

Divide it evenly between the prepared pans and smooth the tops.

Bake for 30 to 35 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs attached.

Allow cakes to cool in the pans for 10 minutes before inverting onto a wire rack to cool completely.

Beat the room temperature butter until creamy in a large bowl.

Add the peanut butter and mix until smooth.

Gradually add the powdered sugar, mixing on low speed until well combined.

Add a pinch of salt and enough water or milk to reach a spreadable texture.

Fold in the chopped Reeses for an extra treat.

Level the cake layers if necessary.

Place the first layer on a cake board, spreading with peanut butter frosting and sprinkles of crumbled Reeses. Repeat with the remaining layers.

Apply a thin crumb coat of frosting around the cake and chill it for about 20 minutes.

After chilling, apply a final layer of frosting smoothly around the cake.

Heat the heavy cream until it’s just simmering, then pour it over the chocolate chips.

Stir the mixture until it’s glossy.

Let it cool slightly and then drizzle it over the frosted cake, garnishing with halved Reeses and more crumbled Reeses.

Chill the cake briefly to set the decorations, then serve at room temperature.