Frosting/filling (from allrecipes.com)
⅔ cup butter
4 cups confectioners sugar
2 tablespoons milk
1 teaspoon vanilla extract
In a medium bowl, cream together the butter, confectioners’ sugar, and milk until light and fluffy, about 3 to 4 minutes. Beat in the vanilla and food coloring. Spread on or between cookies. I felt filling the cookies a day in advance helped the cookies soften a little and mellow the buttercream. I only frosted a small portion as the cookies were great without the buttercream.
* I felt the larger grained turbinado sugar didn't mix quite as well as finer grained white sugar has in previous cookie recipes. Every time I used a cookie cutter, I could hear and feel a grittiness. The taste - no complaints. The smoothness of the cookie top, however, was a little wonky. If decorating with frosting, cosmesis shouldn't be a problem. If you are worried about it, a sprinkling of colored sugar, like I did, camouflages it some.