BLESS THIS MESS
Melt 1 cup of unsalted butter in a saucepan over medium heat. Stir in 2 cups of packed dark brown sugar until well mixed.
Bring it to a boil, stirring for about 1 minute, then remove from heat.
Add ½ cup of milk and whisk until smooth.
Gradually mix in 6 cups of powdered sugar using an electric mixer until you get a spreadable consistency.
Quickly frost your cake, ensuring it's cooled, as this frosting thickens rapidly. Best for 9x13 inch cakes.