Preheat your oven to 350ºF. In a large mixing bowl, combine the cake mix, granulated sugar, flour, and salt. Add the eggs, milk, buttermilk, and sour cream, then beat with an electric mixer for about one minute until everything is well combined. Stir in ¼ cup of the caramel sauce into the batter.

(Ingredients used: 1 box white cake mix, ⅓ cup (66g) granulated sugar, 1 cup (120g) all-purpose flour, ¾ tsp salt, 4 large eggs, 1 cup (236ml) milk, ½ cup (118ml) buttermilk, 1 cup (228g) sour cream, ½ cup jarred caramel sauce)

Prepare a 9×13 inch baking pan by spraying it with non-stick cooking spray. Pour the batter evenly into the pan. Drizzle the remaining ¼ cup of caramel sauce over the batter and use a knife to gently swirl it into the mixture.

(Additional ½ cup jarred caramel sauce)

Bake for 36 to 39 minutes, or until a toothpick inserted into the center of the cake comes out clean. Let the cake cool completely before frosting.

In a medium saucepan over medium heat, melt the butter together with the brown sugar, stirring frequently until fully melted. Allow the mixture to come to a simmer.

(Ingredients: 1 cup (227g) unsalted butter, ¾ cup (161g) brown sugar)

Once simmering, add the heavy cream, stir well, and bring the mixture back to a simmer.

(¼ cup (59ml) heavy cream)

Remove the pan from heat and immediately whisk in the powdered sugar, adding it one cup at a time. It’s fine if some lumps remain.

(3 cups (339g) powdered sugar)

Pour the caramel icing over the cooled cake right away, spreading it evenly as it will set quickly. Allow the icing to cool and set completely before serving.