So simple, it is royal icing, I separate eggs using only the whites , I use 3 eggs whites for about 2 cups of icing sugar(but I have never measured), I whip the eggs whites in my mixer and slowly add icing sugar until I get the right consistency than I add paste food coloring, actually I think the hand mixer is best for this job, and just one beater works better than two, I made this batch a bit thicker for outlining, and then added more egg whites and and icing sugar until it is a little runnier for filling in.
There is not a measurement for this its just by eye , and it is just by trial and error .
When you bag the lining consistency icing , I wet a paper towel and place it at the bottom of a tall glass , to keep the icing bag in so that it does not crust, very important tip, this icing dries very quickly and need to be moves constantly , damp paper towels are handy to prevent drying out, I line the cookie shape and wait 5-10 minutes before filling in the outline, I use a tooth pick to help the icing into the corners.

The cupcake recipe was simple , I bought crushed graham cracker crumbs , and added melted butter and sugar , to make a crust , added them to the papers and pressed down with a glass , baked 8 minutes at 350 , I then used a box mix of devil's food cake chocolate mix added a bit of crust mixture on top before baking , baked following directions and vanilla icing after they cooled ,marshmallow on top , easy easy.
 
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