In advance, using patterns and fondant, roll out and cut broom base and bird. Let dry hard on cornstarch-dusted surface. Cover bird with tip 1 pull-out feathers in royal icing. Add tip 2 pull-out beak, tail, dot eyes and string lashes.
Prepare snowman cake for rolled fondant; cover cake with 48 oz. fondant. Reserve excess pieces. Tint 12 oz. fondant black and 12 oz. Red-Red/Christmas Red combination. Use portion of remaining white fondant to form a 3 1/2 x 8 in. piece for right arm. Position, tapering end to blend piece at shoulder.
Make scarf in 3 pieces: for horizontal piece, roll out and use pizza cutter to cut red fondant into 11 x 2 in. rectangle. Position around neck, shaping folds with fingers. For short vertical piece, roll and cut a 2 1/2 x 4 in. section, cut fringe with scissors and position under horizontal piece. For long vertical piece, roll and cut a 2 1/2 x 8 1/2 in. section; cut fringe and position.
Divide remaining reserved fondant into fourths and tint gray, orange, green and brown. For broom, roll out brown fondant and cover dowel rod. Pinch to form around rod and use spatula to form indentations. Insert broom under arm.
Shape a 1 1/2 in. orange cone for carrot nose; indent with spatula and attach to cake with melted candy. Form black fondant eyes and mouth, white cheeks; attach with candy.
Cover hat area with black fondant, flaring out at top. Cut gray hat band, 3/4 in. wide; indent with spatula and attach with damp brush. For brim, cut a 12 x 2 in. piece of black fondant, fold lengthwise in half, pinch at edge and attach with water; smooth edge with fingers to blend into hat. Using pattern, cut out green fondant holly, roll red balls for berries and attach with melted candy.
Attach broom base piece to broomstick with melted candy; attach marshmallow to side of cake to hold base. Pipe tip 2 outline bristles in royal icing. Attach a band of brown fondant above bristles; indent with spatula. For buttons, roll 5/8 in. diameter balls of black fondant; indent and attach with candy.
Attach bird to broom with melted candy. Pipe tip 2 string feet.