In the bowl of your mixer cream butter and sugar until smooth, at least 3 minutes
Beat in extracts and egg.
In a separate bowl combine baking powder and salt with flour and add a little at a time to the wet ingredients. The dough will be very stiff. If it becomes too stiff for your mixer turn out the dough onto a countertop surface. Wet your hands and finish off kneading the dough by hand.
DO NOT CHILL THE DOUGH. Divide into workable batches, roll out onto a floured surface and cut. You want these cookies to be on the thicker side (closer to 1/4 inch rather than 1/8).
Bake at 350 for 6-8 minutes. Let cool on the cookie sheet until firm enough to transfer to a cooling rack.
Frosting
Lightly combine powdered sugar and meringue powder.
In measuring cup, combine water and vanilla.
Add water mixture to powdered sugar mixture and mix with electric mixer until your frosting is the consistency of toothpaste.
For piping icing, remove some icing and color with food dye to desired color.
For fill icing, slowly add water to icing with a spray bottle to make the icing the consistency of shampoo, slightly runny, but isn't too slick.