1. PREHEAT the oven to 350°F. Cream the butter and brown sugar in the bowl of an electric mixer fitted with paddle attachment, on medium speed, until fluffy. Mix in the spices, then the eggs and molasses. Reduce the speed to low.
2. WHISK together in a separate bowl the flour, salt and baking powder. Add to butter mixture, and mix until just combined.
3. FORM the dough into a disk shape and wrap it in plastic. Refrigerate until cold, about 1 hour.
4. ROLL the out dough on lightly floured work surface or between 2 sheets of parchment paper to about 1/4-inch thick. Cut out the shapes with cookie cutters and cut a small hole in the top of each cookie for the ribbon.
5. PLACE the cookies approximately 2 inches apart on baking sheets lined with parchment paper. Refrigerate until the dough is firm, at least 15 minutes and up to 1 hour.
6. BAKE the cookies until lightly golden, 12 to 14 minutes. Let them cool on the sheets on wire racks.
7. MAKE the royal icing. In the bowl of an electric mixer fitted with the paddle attachment, add the warm water and meringue powder (and the clear vanilla extract if necessary). Whisk by hand until frothy and thickened, about 30 seconds. Add the cream of tartar and whisk by hand for 30 seconds more.
8. ADD all the powdered sugar at once. Using the lowest speed, mix slowly with the paddle for 10 minutes. The icing will become thick and creamy.
9. DIVIDE into portions to tint with food colorings. As necessary, thin the icing with small amounts of warm water to reach the desired consistency.
DECORATING WITH ROYAL ICING
1. BEGIN by piping an icing outline around each cookie. Use a piping bag fitted with a coupler and #2 tip.
2. LET the outline dry for a few minutes to create a solid border. You’ll be able to see the border somewhat when the icing dries, so alternately you could fill or flood your cookie in right after piping the outline. Once you’ve filled the whole cookie…
3. SHAKE it gently left to right on your work surface, to help smooth the icing out.