I have this recipe. I'm not sure where I got it. It is in a binder of torn out pages and notes that are placed in those cute plastic sleeve things Before Kids. When I read magazines. Loved magazines. Worshiped the Martha.
Anyway, this is just the best recipe for those perfect sugar cookies. They hold their shape and are moist.
1/2 lb unsalted butter, softened (don't skimp on this - butter is most important)
1 cup of superfine sugar (regular works if you can't find it)
1/2 tsp salt
1 large egg plus 1 yolk
2 tsp vanilla extract
2.5 cups all purpose flour (plus extra for work surface)
Mix this all up and try not to eat it. Divide it into two sections and put in sprayed syran wrap to chill overnight or at least 2 hours.
When ready to work, only take out a little at a time returning remaining dough to the frig and work 1/8" thick. Line your cookie sheet with parchment paper and put cut cookies spaced evenly apart and put the ready cookie sheet back into the freezer. I do this until all the sheets are ready and bake one or two sheets at a time. This keeps the cut shape when cooking. Bake at 375 for 6-10 min (depending on oven) rotating half way through. They should not be brown and almost be a bit soft when they are done. Cool on a rack.
To ice them, Royal Icing is the best.
460 grams powder sugar
3 level Tbsp. powdered egg white
5 Tbsp water (add more water to get a softer icing for marbling)