In the mixing bowl of a stand mixer, using the whisk attachment, add the Butter, Sugar, Vanilla, Egg, and 2 - 3 drops of Aqua food coloring gel, and blend until light and fluffy. In a separate bowl, add the Flour, and Baking Powder, and stir well to blend. Add the flour a little at a time and mix on low to blend, until all the flour is added. Remove the Whisk attachment, and use the paddle. Continue to blend the Cookie dough until it's completely blended and a smooth ball starts to form. Scrape down the mixing bowl as needed.