Preheat oven to 350°F. Line two 8-inch cake pans with parchment paper and spray with nonstick baking spray. Set aside.

In a large mixing bowl beat together cake mix, instant pudding, eggs, softened butter, buttermilk, vanilla, and caramel until fully combined.

Divide the batter between the two prepared cake pans.

Bake for 30-35 minutes, until the cake pulls away from the sides of the pan and a toothpick inserted in the center comes out with a few moist crumbs.

Cool on wire racks for 5-10 minutes, then remove from pans and cool completely.

Beat together butter and vanilla extract until smooth and creamy.

Add powdered sugar, half at a time, and beat until fully mixed (mixture will be thick).

Add salted caramel while the beater is running and whip until smooth.

Add heavy cream and continue beating until frosting is fluffy. Add additional cream and beat until desired consistency is achieved.

Assembly Instructions:

Level the tops of the cakes with a serrated knife. Place one cake on a serving platter or cake stand.

Pipe a border around the cake and fill with a layer of caramel, spreading to the border.

Top the caramel layer with a layer of frosting, spreading gently so that the caramel layer is not displaced.

Place the second cake layer on top of the filling and press gently.

Frost the assembled cake.

Drizzle the remaining caramel over the top of the frosted cake, spreading gently just to the edges so that it drips over the edge and down the sides.

Decorate as desired with a border and/or swirls of frosting on the top of the cake.

Sprinkle with flaky sea salt and serve.