I am new to cake decorating and I need a crusting butter cream that I can try smoothing with a paper towel. I would really like a recipe that doesn't have to be refrigerated. Thanks for your help

Try the one that wilton has. It works well for me with the viva towel thingy...

1/2 c real butter, 1/2 c Crisco, 1 tsp. vanilla, and 4 c powdered sugar, sifted. Cream butter and crisco together then add vanilla. Then add sifted sugar 1c at a time. When all mixed, add 1-2 tablespoons of milk and mix until fluffy. Ice your cake and let it set up about 15 min or so, until you icing crusts, then use your paper towel. Good Luck, and I hope that this helps!