Combine cream, Cointreau and powdered sugar in medium bowl. Beat until medium-firm peaks form. (Can be made 4 hours ahead. Cover and refrigerate.) Pour 2 tablespoons Irish cream liqueur, 1 tablespoon whiskey and 1 tablespoon brandy into each of four 8-to 10-ounce coffee mugs. Pour hot coffee over. Top each with a dollop of whipped cream. Sprinkle with grated orange peel and serve immediately.