In a medium sized bowl, whisk together flour, baking powder, and salt.

In the bowl of an electric mixer beat butter on medium high speed until smooth, scraping down the bowl as needed. Add sugar and beat until light and fluffy, about 5 minutes. Beat in egg and vanilla extract.

With the mixer on low speed, slowly add flour, beating until just incorporated.

Preheat the oven to 350 degrees. Line two baking sheets with parchment paper. Lightly flour a workspace.

Turn the dough out onto the floured work area. The dough will be a little crumbly, so use your hands to knead it together into a cohesive ball. Using a floured rolling pin, roll the dough out to 1/4 in thick. Cut shapes as desired then place them on the parchment lined baking sheets. Place baking sheets in the freezer for about 10 minutes, then bake for 10-14 minutes or until cookies are set, but not browned. Allow to cool on the tray for about 5 minutes to set up, then remove and cool completely.

In the bowl of an electric mixer fitted with the paddle attachment, beat together meringue powder and water until foamy.

Add the sifted powdered sugar (yes, you HAVE to sift. Yes, I know it's a pain. Yes, it will make your icing so much easier to work with). Beat on low to combine.

Add the corn syrup and vanilla extract and beat. Increase speed to medium high and beat until stiff peaks form. The icing should hold a peak and not droop over when it's ready.

Divide icing among different bowls to add food coloring as desired. Use the stiff icing to pipe around the outside of cookies and add details. To flood (fill) the cookies with color, add water 1 teaspoon at a time, until icing runs off the back of a spoon.