1. Whisk together flour, baking soda, and baking powder into a large bowl. Set aside.

2. Place butter and brown sugar in the bowl of an electric mixer fitted with the paddle attachment; mix on medium speed until fluffy. Mix in spices and salt, then eggs and molasses. Reduce speed to low. Add flour mixture; mix until just combined. Divide dough into thirds; wrap each in plastic. Refrigerate until cold, about 1 hour.

3. Preheat oven to 350 degrees. Roll out dough on a lightly floured work surface to 1/4-inch thick. Using creche-shaped cookie cutters, cut one center piece and two end pieces. Transfer to baking sheet. Stick two toothpicks in the bottom edge of each cookie.

4. Bake cookies until crisp but not dark, 12 to 14 minutes. Let cool on sheets on wire racks.

5. Meanwhile, mix together royal icing with brown gel paste until desired dark brown shade is reached. Transfer to a small squirt bottle with a wide tip. Draw a wood or faux-bois design on creche. Let dry completely before assembling on foam or on a cake.