Preheat the oven to 350°F (175°C). Grease and flour a 9-inch round cake pan.
In a mixing bowl, cream together the butter and sugar until light and fluffy.
Add the brewed coffee and mix until well combined.
In a separate bowl, sift together the flour, baking powder, baking soda, and cocoa powder.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined.
In another bowl, whisk together the eggs, sour cream, and vanilla extract.
Fold the egg mixture into the batter until smooth.
Pour half of the batter into the prepared cake pan.
Drizzle half of the caramel sauce over the batter.
Pour the remaining batter over the caramel sauce.
Bake in the preheated oven for 30-35 minutes, or until a toothpick inserted into the center comes out clean.
Let the cake cool in the pan for 10 minutes, then transfer to a wire rack to cool completely.
Drizzle the remaining caramel sauce over the top of the cake before serving.