In a standing mixer with the whisk attachment add mix the powdered sugar, meringue powder and 4 tbsp of water
Add the vanilla extract and stir until combined
Slowly add the remaining 4 tbsp of water while the mixer is on low
Once all the ingredients are added, turn the mixer on high and beat for 2 minutes
Once done, add frosting to a piping bag and get decorating
It will take about 2 hours for the frosting to set on cookies, if using on a gingerbread house, it is helpful to have a fan on close by while building the house. The fan will help set the frosting up a bit quicker & glue your house together.