Preheat your oven to 350°F (175°C).
Grease and flour two 9-inch round cake pans.
In a large mixing bowl, cream together the butter and granulated sugar until light and fluffy.
Add the eggs one at a time, beating well after each addition. Then, mix in the vanilla extract.
In another bowl, whisk together the flour, baking powder, baking soda, and salt.
Alternate adding the dry ingredients and buttermilk to the butter mixture, starting and ending with the dry ingredients.
Pour the batter evenly into the prepared cake pans and smooth the tops.
Bake for 25-30 minutes, or until a toothpick inserted in the center comes out clean.
Allow the cakes to cool in the pans for 10 minutes before transferring them to a wire rack to cool completely.
In a saucepan, combine the sugar and corn syrup to make the caramel icing.
Heat over medium heat until the sugar dissolves, then let it come to a gentle boil.
Once the mixture reaches a deep amber color, remove it from the heat and slowly whisk in the heavy cream and salt.
Allow the caramel icing to cool slightly before spreading it over the cooled cake layers.
Layer the cakes and cover the top and sides with the caramel icing.
Let the cake sit for about 30 minutes before slicing and serving.