Preheat the oven to 350ºF. Grease and flour 2 9" round cake pans. Or use cake release.
In the bowl of a stand mixer with the paddle attachment (or using a hand mixer), cream together the butter and sugars until fluffy.
Add eggs and vanilla and beat thoroughly. Scrape the sides of the bowl as needed.
In another bowl, whisk together the baking soda, salt, baking powder and cake flour.
Add dry ingredients to the creamed butter alternately with the buttermilk, beating thoroughly after each addition.
Pour the cake batter evenly into the prepared cake pans.
Bake for 25 minutes or until the center of the cake bounces back when you touch it.
Allow the cakes to cool for 10 minutes, then loosen the edges and turn out on a wire rack to cool completely.
Make the buttercream:
At least an hour before making the frosting, melt the caramels. Place the caramel bits in a microwave safe bowl and add the evaporated milk. Microwave in 20-30 second intervals, stirring between, until caramels are smooth and completely melted. This will take 2-3 minutes.
Allow the caramel to cool completely to room temperature. This is important! If you add the caramel when it is too warm, it will melt the butter in the frosting and it will not set correctly.
In a large bowl, beat together the cream cheese and butter using a hand mixer until well combined.
Add the powdered sugar and the vanilla extract. Beat again.
Add the cooled caramel to the frosting and beat for 2-3 minutes, scraping the sides of the bowl as needed.
Frost the cake:
Place one cake layer on a cake plate. Frost the top with frosting.
Then place the other cake layer on top. Frost the entire outside of the cake with frosting, making it as smooth as possible.
Make the drizzle:
Place 5 ounces of caramel bits in a microwave safe bowl and add the evaporated milk. Microwave in 20-30 second intervals, stirring between, until caramels are smooth and completely melted. This will take 2-3 minutes.
Allow the caramel to cool completely to room temperature, then drizzle the caramel over the cake.
Sprinkle with 1/2 teaspoon coarse sea salt.
Store the cake in an airtight container at room temperature for up to 24 hours, then refrigerate.
Notes
Refer to the article above for more tips and tricks.The calories shown are based on the cake being cut into 15 pieces, with 1 serving being 1 slice of cake. Since different brands of ingredients have different nutritional information, the calories shown are just an estimate. **We are not dietitians and recommend you seek a nutritionist for exact nutritional information. The information in the nutrition box are calculated through a program and there is room for error. If you need an accurate count, I recommend running the ingredients through your favorite nutrition calculator.**