Preheat oven to 350 degrees.
Make the Salted Caramel - Pour sugar in a medium saucepan over medium-high heat. Whisk until the sugar has completely melted. Allow the sugar to get nice and bubbly brown.
As soon as your sugar turns that beautiful deep amber caramel color, add the butter and whisk until your butter has melted.
Turn off your burner and add the whipping cream
Whisk until all of the half and half has been combined.
Add the sea salt and stir.
In a small bowl, combine the sweet potato, butter, brown sugar, whipping cream, vanilla, cinnamon and nutmeg with an electric mixer.
In another small bowl, combine the cream cheese, powdered sugar and vanilla and beat well.
Put the bottom half of each bun in a 9X9 casserole dish.
Top each bottom bun with 1 T. of the sweet potato mixture, about 1 tsp. of the cream cheese mixture and finally the top half of each bun.
Pour all of the salted caramel over the tops of the buns and sprinkle with the toasted walnuts.
Place the casserole in the oven for about 15 minutes to heat through. Say Grace and enjoy!