Recipe from Dorie Greenspan Baking From My Home to Yours
2 cups all purpose flour
1/2 teaspoon salt
1/2 teaspoon double-acting baking powder
1 stick plus 2 tablespoons (10 tablespoons total) unsalted butter at room temperature
1 cup sugar
1 large egg
1 large egg yolk
1 teaspoon pure vanilla extract
Whisk the flour, salt and baking powder together and keep close by.
Working in a mixer with the paddle attachment, if you have one, beat the butter at medium speed for a minute or so, until it is smooth. Still beating, add the sugar and continue to beat for about 2 minutes, until the butter is light and pale. Add the egg and the yolk and beat another minute or two. Reduce the mixer speed to low and steadily add the flour mixture, mixing only until it has been incorporated. When mixed, the dough will be soft, creamy and appealingly malleable.
Turn the dough out onto a counter and divide it in half. Shape each half into a chubby sausage (the diameter of the sausage is up to you - I usually like cookies that are about 2 inches or more across) and wrap in plastic. Chill the packets for at least 2 hours. (Well wrapped, the dough can be refrigerated for up to 3 days or frozen for up to 2 months.)
Center a rack in the oven and preheat the oven to 350 degrees F. Have two lined baking sheets ready. You will want to cut the dough at 1/4-inch intervals with a sharp thin-bladed knife, place the slices of dough rounds on one of the baking sheets, leaving about 1 1/2 inches of space between each cookie.
Bake the cookies, one sheet at a time, for 9 to 11 minutes, rotating the sheet at the mid-point. The cookies should feel firm, but they should not color much if at all. Let cool on a wire rack. At this point they can be eaten or you can frost them with my frosting below!
1 cup confectioners sugar
2 1/2 - 3 teaspoons heavy cream
1/4 teaspoon vanilla extract
Sprinkles for decorating (optional but highly suggested)
In a small bowl, place the confectioners sugar. Add in the heavy cream and vanilla and stir to combine. The mixture should be thick like icing. If it's too thick, add a little more heavy cream, until its the desired consistency. Place a small dollop of icing on each cookie and spread it around. Top with sprinkles.