This fudge icing recipe is meant to accompany the "King Cake" recipe.
1 1/2 cups brown sugar
1/2 cup light cream
1 tablespoon butter
Mix sugar and cream in a pot and boil gently until mixture forms a soft ball when dropped into cold water. Remove from heat and add butter. Beat mixture until it starts to thicken and crystallize. Immediately spread on the cooled cake.
From The 1994 Old Farmer's Almanac, Canadian Edition