Pinch of kosher salt
1/4 cup Heavy cream
1 tsp. Pure vanilla extract
1/4 cup Sour cream
6 cups Powdered sugar
1 1/2 cups Butter, softened
1/2 cup Sprinkles, plus more for garnish, if desired
1 1/4 cups Milk
1 tsp. Kosher salt
2 tsp. Baking powder
1/4 cup Cornstarch
3 cups All-purpose flour
1 tbsp. Pure vanilla extract
4 Large eggs
2 1/4 cups Granulated sugar
1 1/2 cups Butter, softened