These cookies are a designer's dream. Give them to a designer friend to make them squeal, or make them for yourself so you can eat your favorite colors. The cinnamon in the sugar cookie contrasts nicely against the sweetness of the icing. These cookies take a little time, especially the icing process, so be patient.
Whisk together flour, salt, baking powder and cinnamon in a medium bowl and set aside. With an electric mixer fitted with the paddle attachment, cream butter and sugar until light and fluffy. Add egg and vanilla and continue to mix until well-combined. In three batches, add reserved flour mixture and mix until just combined.
2 cups all-purpose flour, 1/4 teaspoon salt, 1/4 teaspoon baking powder, 1 teaspoon cinnamon, 1/2 cup unsalted butter, 1 cup sugar, 1 large egg, 1/2 teaspoon vanilla extract
Separate dough into two balls and wrap in plastic wrap. Flatten into a disc and refrigerate for at least 1 hour.
Pre-heat oven to 350℉. Line baking sheets with non-stick baking mats or parchment paper and set aside.
Roll out dough to 1/8-inch thickness on a lightly floured work surface. Using a rectangular cookie cutter or knife, cut dough into rectangles and transfer to prepared baking sheets, leaving an inch in between. Bake until lightly golden, about 10 minutes. Do not allow the cookies to brown. Remove from oven and let sit for 2 minutes before transferring to wire racks. Let cool completely.
For the icing
Add confectioner's sugar, meringue powder and 1/5 of the water to the bowl of an electric mixer. With an electric mixer, beat ingredients on low speed until smooth, about 7 minutes. If icing is too thick, add more water; if too thin, beat 2 to 3 minutes more.
1 pound confectioners' sugar, 5 tablespoons meringue powder, 1/2 scant cup water
Separate icing into as many bowls as you need colors. For white, don't dye the icing. In small batches, dip toothpicks in icing color, then swirl them in the icing to add color. With a spoon, stir the color in. Repeat until you have a slightly lighter color than desired, as the icing will darken slightly as it dries and hardens.
3-4 drops food color
Decorating the cookies
Spoon icing into piping bags or plastic zip-lock bags and snip a small corner off the bag with scissors. Test the pressure of the icing on a plate or wax paper. Pipe squares of color and rectangles of white to look like a Pantone chip. Use an icing spatula or butter knife to smooth, if necessary.
Let harden completely. If desired, write "Pantone" and the color's PMS number on the white part of the icing with a black food color marker. Store in airtight container. (The cookies can be frozen in an airtight container. Let container reach room temperature before opening to avoid condensation and discoloration on the cookies.)
1 food color marker
Notes
*I halved this recipe, making less icing and storing the rest of the cookie dough in the freezer for use at a later date.**For Radiant Orchid, I used Wilton's Aster Mauve, which has been discontinued, combined with Burgundy and Royal Blue. I think the Burgundy and Royal Blue would be just fine on their own, though!