Preheat the oven to 350 degrees F (325 degrees F in a convection oven). Line cupcake pans with cupcake liners (24 regular size or 48 mini size).
Using a standing mixer fitted with a paddle attachment, mix the sour cream, baking soda, salt and eggs until combined. Scrape out the insides of the vanilla bean. Add the vanilla and granulated sugar to the egg mixture. Mix until combined.
In a small bowl, mix the melted butter with 1 cup water. With mixer set to a low speed, alternate adding the water and butter, with the flour. Scrape down the sides of the bowl and continue mixing until well combined.
Fill the cupcake liners two-thirds full with the batter. Bake until golden brown and baked through, 22 minutes for regular size and 16 minutes for mini size. Cool the cupcakes completely. Frost with the Caramel Buttercream Frosting. Garnish if desired.
Using a standing mixer fitted with a paddle attachment, add the butter and beat until smooth, 2 to 3 minutes. Add the cream cheese and beat until fully incorporated and smooth. Reduce the speed and add the powdered sugar a little at a time. Mix until fully incorporated. Add the caramel sauce to the buttercream mixture.
This recipe was created by a contestant during a cooking competition. It has not been tested for home use.