In a large mixing bowl, combine powdered sugar, butter, vanilla, almond extract and egg. Beat until smooth.
Add flour, baking soda and cream of tartar. Mix until smooth.
Spread dough in a thin even layer in a 9 x 13 baking pan. Bake until just beginning to brown, 10-15 minutes. Remove from oven and cool
Combine powdered sugar and cherry juice. Thin to spreading consistency with milk.
Frost cookies, add sprinkles, cut into bars
Cut Out Cookie Variation:This cookie dough is wonderful for cut out cookies if you prefer. Just chill the dough for at least an hour before rolling and cutting, then bake until just beginning to brown, about 7-8 minutes.