Preheat the oven to 350°F (175°C).
Grease and flour two 9-inch round cake pans.
In a large mixing bowl, combine the flour, sugar, cocoa powder, baking soda, and salt.
In another bowl, whisk together the eggs, melted butter, Kahlua, and vanilla extract.
Add the wet mixture to the dry ingredients and mix until just combined.
Divide the batter evenly between the prepared pans.
Bake for 25-30 minutes or until a toothpick inserted comes out clean.
Allow the cakes to cool in the pans for 10 minutes, then transfer to a wire rack to cool completely.
While cooling, make the frosting by whipping together the powdered sugar, heavy cream, and Kahlua.
Once cooled, frost the tops of one cake layer, place the second layer on top, and frost the top and sides.
Let the cake sit for about 30 minutes before serving.
