Preheat your oven to 350°F and prepare two 9-inch round cake pans with parchment paper and light greasing. Ensuring proper pan preparation prevents sticking and guarantees clean cake removal for impressive presentation.

Whisk together flour, cocoa powder, baking soda, and salt in a large bowl until fully combined. Set this dry mixture aside while you prepare the wet ingredients for the gooey caramel cake.

In another bowl, beat granulated sugar, brown sugar, and eggs together for 3 minutes until pale and fluffy. Add oil and vanilla extract, mixing until fully incorporated before introducing the buttermilk gradually.

Alternate adding the dry mixture and hot water to the wet ingredients, beginning and ending with dry ingredients. Bake for 33-35 minutes until a toothpick inserted in the center emerges with minimal crumbs, indicating perfectly baked layers.

Cool the cake layers completely before assembly—at least 90 minutes is essential for structural integrity. While cooling, warm the caramel sauce slightly and mix heavy cream with butter to create a silky frosting consistency.

Place the first chocolate layer on your serving plate, then spread half the warm caramel sauce evenly across the top. Add the second layer and spread remaining caramel sauce, allowing some to drip down the sides for visual drama.

Pour the caramel-cream frosting over the top, letting it cascade naturally down the sides for that signature restaurant-quality appearance. The chocolate caramel cake deserves a resting period of at least 4 hours before slicing to allow layers to set properly.