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

In a medium bowl, sift together the flour, baking powder, baking soda, salt, and cocoa powder. Set it aside.

In a large bowl, cream the softened butter and granulated sugar until the mixture becomes light and fluffy.

Add the eggs one at a time, mixing well after each addition. Then stir in the vanilla extract.

Gradually add the dry ingredients to the wet ingredients, alternating with the buttermilk. Mix until just combined.

Fold in the chopped pecans or walnuts and 1 cup of caramel sauce.

Divide the batter equally between the prepared cake pans and smooth the tops.

Bake for 25–30 minutes or until a toothpick inserted into the center comes out clean. Let the cakes cool in the pans for 10 minutes before transferring them to wire racks to cool completely.

Once cooled, place one layer of cake on a serving platter. Spread a layer of chocolate frosting on top, followed by a drizzle of caramel sauce.

Place the second cake layer on top and frost the top and sides with the remaining chocolate frosting.

Drizzle additional caramel sauce over the top and garnish with more chopped nuts if desired.