Step 1

Preheat the oven to 350º F.

Step 2

In a large mixing bowl combine the cake mix, sugar, flour, and salt. Add in the eggs, milk, buttermilk, and sour cream, beat with an electric mixer until combined, about 1 minute. Add 1/4 cup of the caramel sauce, mix into the batter.

Step 3

Spray a 9x13 inch pan with non-stick cooking spray. Pour the batter into the pan. Drizzle the remaining 1/4 cup caramel on top of the batter and use a knife to swirl the caramel into the batter.

Step 4

Bake for 36-39 minutes or until a toothpick inserted in the center of the cake comes out clean. Allow the cake to cool completely before adding frosting.

Step 5

In a small-medium sized pot over medium heat on the stove, melt the butter and brown sugar. Stir frequently until melted. Allow the mixture to come to a simmer.

Step 6

Once simmering, add in the heavy cream, stir and allow the mixture to return to a simmer.

Step 7

Once it simmers again, remove it from the heat and immediately whisk in the powdered sugar, one cup at a time. It’s okay if there are a few powered sugar lumps.

Step 8

Immediately pour the caramel icing over the cooled cake (the icing will set quickly so be sure to move fast) and spread into a even layer. Allow the icing to set and cool before serving.