- Beat all ingredients at low speed for 7-10 minutes (10-12 minutes at high speed for portable mixer) until icing forms peaks. Makes 3 cups.
- Buttercream Icing:
- Cream butter and shortening with electric mixer. Add vanilla. Gradually add sugar, one cup at a time, beating well on medium speed. Scrape sides and bottom of bowl often. When all sugar has been mixed in, icing will appear dry. Add milk and beat at medium speed until light and fluffy. Keep icing covered with a damp cloth until ready to use. For best results, keep icing bowl in refrigerator when not in use. Refrigerated in an airtight container, this icing can be stored 2 weeks. Rewhip before using. Makes 3 cups.
- Make hats using scissors to cut cone to 3-1/2" by snipping in small increments along open end.
- Cover cone with tip 4 zigzags in royal icing (smooth with finger dipped in cornstarch). For a smooth finish, cover cones again with thinned royal icing; let dry.
- Using full-strength royal icing, pipe tip 47 (smooth side up) double-width outline hat band; smooth with spatula.
- Pipe tip 3 outline buckle and tip 4 dots (pat smooth with finger dipped in cornstarch).
- Bake and cool cupcakes in silicone cups supported by cookie sheet.
- Ice smooth with buttercream icing.
- Pipe tip 127D ruffle brim, letting 1/4" of ruffle extend over edge.
- Position hats onto cupcakes.