In advance: Make hat. Combine 1/2 teaspoon of Gum-Tex to 1 pack of violet fondant. Shape a 1 x 1 in. log for top of hat. Roll out remaining violet fondant 1/8 in. thick; cut brim using medium Cut-Out. Attach brim to hat with damp brush. Roll out yellow fondant 1/8 in. thick. Using knife, cut a 1/8 in. wide strip for hat band; attach with damp brush.
For holly, roll out green fondant 1/8 in. thick. Cut leaf shapes with knife. Use tip 9 to cut scalloped edges. Attach to hat with damp brush. For berries, roll 1/8 in. balls of red fondant; attach with damp brush.
Bake and cool cupcakes in silicone cups supported by cookie sheet. Decorate with buttercream icing. Using tip 12, pipe a mound of white icing on top and smooth with spatula. Pipe tip 3 dot eyes in white, pupils and outline mouth in black. For nose roll a 3/4 in. ball of orange fondant; attach with icing. For scarf, roll out yellow fondant 1/8 in. thick. Using knife, cut a 3/8 in. wide strip; attach with icing. For ends, cut two 3/8 x 1 1/2 in. strips; score fringe with knife and attach with damp brush.