Mardi Gras King Cake

INGREDIENTS

• :
• 2 tablespoons unsalted butter
• 8 ounces sour cream
• 5 tablespoons granulated sugar, divided into 4 tablespoons & 1 tablespoon
• Pinch of salt
• 1 package (2¼ teaspoons) active dry yeast
• ¼ cup warm water (between 100 and 110 degrees)
• 1 egg
• 3 to 3½ cups all-purpose flour
• Oil for your hands and the bowl
• 2 teaspoons cinnamon
• ½ cup granulated sugar
• 4 tablespoons of melted butter
• 2 cups powdered sugar
• 1 teaspoon vanilla extract
• 1 tablespoon unsalted butter, melted
• 4 tablespoons whole milk
• 1½ cups superfine sugar (not powdered sugar), separated into ½ cups
• Food coloring - Yellow, Green, Blue & Red