Cookie Instructions:

1. Whisk the flour, baking powder, and salt together in a medium bowl and set aside.
2. In a large mixing bowl, beat the softened butter and sugar until light and creamy, about 3 minutes. Scrape the bowl as needed to ensure even mixing.
3. Add the egg and vanilla and mix until fully combined.
4. Add the dry ingredients and mix on low speed just until a soft, workable dough forms. The dough should feel smooth and pliable, not sticky. If needed, add additional flour 1 tablespoon at a time, stopping as soon as the dough releases cleanly from the bowl.
5. Divide the dough in half. Place each portion on lightly floured parchment paper or a silicone baking mat and roll immediately to an even ¼-inch thickness.
6. Cut into shapes using cookie cutters. Gather and reroll scraps as needed. Transfer cut cookies to parchment-lined baking sheets, spacing them about 2 inches apart.
7. Bake at 350°F (177°C) for 10–12 minutes, removing the cookies when the edges are set and the tops remain pale. Avoid browning the edges.
8. Let the cookies cool on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely. For best decorating results, chill the cooled cookies briefly before icing.

Royal Icing Instructions:

1. Combine the powdered sugar and meringue powder in a mixing bowl.
2. Add 7 tablespoons of water along with the vanilla. Beat on high speed for 1–2 minutes, until the icing falls back into itself and smooths out within 5–10 seconds.
3. Adjust the consistency with small additions of water or powdered sugar as needed. Keep the icing covered when not in use.
4. For piping, reserve about ¼ of the icing for outlining (thicker consistency) and ¾ for flooding (thinner consistency).
5. Divide the icing into separate bowls for coloring and tint with gel food coloring, mixing thoroughly.

Decorating Instructions:

1. For piping (multiple colors): Outline the edges of a chilled cookie with icing and allow the outline to set. Once firm, fill in the sections with flood icing and let dry completely.
2. For dipping (single color): Dip the top of a chilled cookie into a shallow bowl of icing, allow excess to drip off, then set upright to dry. Once the icing has hardened, additional details can be piped on top.
3. Allow royal icing to harden fully—typically within 2–6 hours, depending on thickness and humidity.