Pre-heat oven to 350 degrees.
Line baking sheets with parchment.
Have cookie cutter(s) ready.
COOKIES:
In medium bowl add the flour, salt and baking powder, stir to combine, set aside.
In bowl of mixer start whipping the butter until light and fluffy.
Add the sugar and mix to combine.
Add in the egg and extracts. Mix well to combine.
Slowly add in the flour mixture and mix until cookie dough forms and all is combined.
Divide dough into two portions.
Place dough between two sheets of wax paper and roll out, cut out cookies and place on tray.
Bake for 8-12 minutes.
Repeat until all cookies are baked.
Let cool completely.
ROYAL ICING:
Pour water into bowl of mixer fitted with whisk attachment.
Beat meringue powder into cold water until peaks form.
Beat in the powdered sugar until desire consistency is reached.
If stiffer icing is desired add more powdered sugar.
If thinner icing is desired add more water.
Pour into piping bag with a small round tip, I used Wilton tip #3.
DECORATING:
Lay cookies flat on cookie sheets.
Outline the cookies with royal icing.
Let set for at least 10 minutes. This outline will be like a fence and will keep the royal icing from running over the sides when its time to fill.
Next fill each cookie with royal icing (if too stiff add a little water until desired consistency is reached, using the tip or a toothpick to move it around so it covers evenly.
Sprinkle immediately with sprinkles while icing is wet.
Let set to dry completely, at least 4 hours but over night is preferable.
If using luster dust make sure royal icing is completely set.
Mix a little luster dust with some lemon extract and paint luster dust onto cookies. Let dry.