Step 1: Whisk the powdered sugar and meringue powder together in the clean bowl of a stand mixer.

Step 2: Add the warm water and clear vanilla extract to the dry ingredients.

Step 3: Beat the mixture on medium-low speed for about 5 minutes until stiff peaks form.

Step 4: Gently fold in the vegetable glycerin or light corn syrup until fully incorporated to lock in the bakery-style shine.