Step 1: Preheat your oven to 350°F (175°C).
Step 2: Grease and flour your round cake pans.
Step 3: In a medium bowl, whisk together the flour, baking powder, baking soda, and salt.
Step 4: Beat the butter and sugar on medium speed until light and fluffy, about 3-4 minutes.
Step 5: Add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract.
Step 6: Gradually add dry ingredients to the butter mixture, alternating with buttermilk.
Step 7: Divide the batter between the prepared pans and bake for 25-30 minutes.
Step 8: Let the cakes cool in the pans for about 10 minutes, then transfer to wire racks.
Step 9: Beat the butter until creamy, then gradually add powdered sugar, cocoa, and salt. Mix until combined, then add corn syrup, vanilla, and melted chocolate.
Step 10: Once the cakes are cool, frost the top of one layer, place the second layer on top, then frost the top and sides of the cake.
Step 11: Slice and serve to enjoy!