Mix cocoa and flour in 2-quart saucepan. Stir in brown sugar, milk, cloves, and 1 stick cinnamon. Heat just to boiling over medium heat, stirring constantly; reduce heat. Simmer uncovered for 5 minutes (Do Not boil). Remove from heat; remove cloves and cinnamon. Stir in powdered sugar and vanilla. Beat with molinillo, wire whisk or hand beater until foamy. Pour into 4 cups or mugs. Serve with whipped cream and cinnamon sticks.