Make sure the Caramel Sauce is made ahead of time.

Preheat the oven to 350°F. Line three 6-inch cake pans with parchment paper.

To make the batter: In the bowl of a stand mixer fitted with the paddle attachment, add the butter, cane sugar, and vanilla extract and mix no low until combined and there are no chunks of butter. Add the eggs, milk, and sour cream and mix on low until combined, scraping down the sides of the bowl.

In a separate bowl, add the cake flour, baking powder, and sea salt and whisk together. With the mixer on low, slowly add the flour mixture to the butter mixture. Continue to mix on low until you don’t see any specs of flour, scraping down the sides of the bowl. Divide the batter evenly into the prepared pans, about 226 grams each.

Bake for 20 minutes or until a toothpick inserted in center comes out clean. Allow to cool completely in the cake pans. (If you're baking at high altitude, be sure to check the Notes at the bottom of the recipe for high altitude baking instructions).

To make the frosting: In the bowl of a stand mixer fitted with the paddle attachment, add the powdered sugar, butter, and caramel sauce. Mix on low until combined, then speed mixer up to high for 1 to 3 minutes or until light and fluffy.

To assemble the cake: Place a dollop of frosting on a cake stand or cake spinner and add the first cake layer. Using a cake spatula add a layer of frosting to the top of the cake. Drizzle with caramel sauce and sprinkle it with sea salt. Place the second cake layer on top, and repeat this process to crumb coat the cake completely.

Frost the cake with some texture and add caramel sauce all over the top. Sprinkle the top with sea salt.