To make cookie dough, combine butter and sugar in bowl of aelectric mixer. Beat together on low speed, then increase to medium-high speed and continue to beat until smooth and fluffy, about 2-3 minutes. Blend in salt and vanilla extract. Scrape down sides of bowl and blend in egg. With mixer on low speed, add in baking powder and flour and mix just until dough forms. Form dough into ball, wrap tightly in plastic wrap and refrigerate until firm, at least 2 hours.
When you are ready to bake the cookies, preheat the oven to 350?F. Line baking sheets with parchment paper or silicone baking mats. Place cookie dough on lightly floured work surface and roll into even layer, about 1/4-inch thick. Use heart cookie cutters of various sizes to cut out cookie shapes, and place on prepared baking sheets.
Bake, rotating sheets halfway through, until tops are just set and bottoms are beginning to brown, about 9-10 minutes total. (The edges and tops should not brown.) Remove from oven. Let rest for a few minutes, then transfer to wire rack to cool completely.
Combine powdered sugar, meringue powder and water in bowl of stand mixer fitted with paddle attachment. Mix on low speed until sheen has disappeared and icing has a matte appearance (about 5 minutes). This will be the stiffest consistency of the icing, and at this point it is still too stiff to use for decorating. Add water, a very small amount at a time, and stir each addition until fully incorporated. Continue until icing has reached a consistency appropriate for piping. Test small portion to ensure that it is not too stiff or too runny. Once you have reached a workable consistency, divide icing into separate bowls and tint one portion red, one pink and one purple. Leave one portion white.
Transfer icing to pastry bags fitted with small round tips. Pipe and flood face portion of bugs and let set a few minutes before piping wings in alternate colors. Let the head and wings dry at least 4-5 hours before using remaining icing to make dots on the wings. Use smaller piping tip to make tiny heart shapes for mouths and eyeballs. Tint any leftover white icing black and use toothpick dipped in black icing to make pupils on eyeballs. Let dry completely.