Tint 12 oz. white rolled fondant a light teal. Divide remainder of fondant equally; tint dark teal, ivory, medium violet, dark violet, and reserve some white.
Mix 8 oz. light teal fondant with 3/4 teaspoon Gum-Tex (if desired). Roll out 1/8 in. thick; cut 12 1 in. wide x 7-1/2 in. long strips . With Cutter/Embosser, lightly score strips about 3/16 in. in from each long edge. Fold each strip to form loop; adhere ends with damp brush. Trim off corners of bow loops to form an outward "V" shape. Allow loops to dry on cornstarch dusted surface; support with crushed tissue inside the loop. Using large round cutter, cut a fondant circle to make base for bow; let dry.
Assemble bow on round base as follows, using fondant adhesive: On bottom layer, 5 loops; middle layer 5 loops arranged alternately between bottom layer loops; 2 loops upright on top. Set aside to dry completely.
Bake and cool a 2 layer 6-in. round cake. Stack cooled cake layers on separator plate using buttercream icing as a filling; spatula ice stacked cake.
Roll fondant ropes about pencil width and as long as your cake is high. Crush Cake Sparkles through tea strainer. Brush ropes with water; sprinkle with cake sparkles. Position ropes side by side on cake, securing with dots of icing if necessary. Trim logs even with top of cake, if needed. Place bow on top of cake.