¼ tsp baking powder
¼ tsp salt
⅔ cup confectioners' sugar
¼ cup granulated sugar
20 Tbsp 1/2 pound plus 4 tablespoons (2 1/2 sticks) butter, cut into pieces and kept very cold
1 tsp vanilla extract
½ tsp clear flavoring extract
½ tsp rose (or other) gel food coloring
1 ½ cup jumbo multi-colored nonpareil
Combine 2 cups of the flour with the baking powder, salt, and sugars in a food processor, and pulse briefly to mix. Add the cold butter in pieces; process with short bursts until the mixture has a crumbly consistency. Add the vanilla extract and process in 3-second pulses until a dough ball forms.
Divide the dough in half and return one portion to the food processor. Add the clear flavor extract, gel food coloring, and the remaining 2 tablespoons of the flour to the processor and process until just incorporated.
Roll out each portion of dough between sheets of wax paper to form a rectangle about 11 x 8 1/2 inches x 1/8 inch thick. Transfer the rolled dough inside the wax paper onto a large cookie sheet. Refrigerate until firm, at least 2 hours.
Remove the dough pieces from the refrigerator.
Pour the nonpareil decors into a shallow rectangular dish, such as a standard 9 x 13-inch pan. Peel off the top sheet of wax paper from both pieces of dough. Using a pastry brush, lightly coat the vanilla dough with water.
Using the wax paper, lift the red dough and flip it over onto the vanilla dough so they are stacked. Gently press the two dough pieces together. Remove the top sheet of wax paper and trim the edges of the dough square.
When the dough is just pliable but still cold, roll it up along the longest side like a jelly roll. Gently curl the edge with your fingertips so you don't get any air pockets as you roll the dough into a log. While rolling the dough, the vanilla portion (which will be on the outside of the roll) may want to tear; pinch tears together as they happen and keep rolling.
After forming the dough into a log, dispose of the wax paper. Gently lift the log and place it on top of the nonpareils in the dish. Roll until the log is completely coated with sprinkles. Wrap the log in plastic wrap and refrigerate until firm enough to slice, about 3 hours.
Preheat the oven to 325°F. Line 2 baking sheets with parchment paper.
Slice the dough into ¼-inch-thick cookies, cutting carefully and avoiding the nonpareils, and bake on parchment-lined baking sheets for 15 to 17 minutes. When done, cookies should no longer be shiny on top and the bottoms should be lightly browned.
Note: Cookie dough can be frozen up to 2 months.
Reprinted with permission from Dessert Recipes to Inspire Your Inner Artist by Heather Baird, 2012. Published by Sterling Epicure, an imprint of Sterling Publishing Co.