Add the powdered sugar, meringue powder, corn syrup, pinch of salt, vanilla, almond, and butter extracts (make sure to see my note on this!), and 5 tbsp of water in your mixing bowl.

Turn your stand mixer on low just until all of the ingredients are incorporated - about 20 seconds.

Turn off the mixer, scrape the sides of the bowl, and then turn the mixer onto medium speed and allow to mix for 4 minutes. (I consider medium speed to be at the “4” mark on my KitchenAid stand mixer.)

Turn off the mixer and check the consistency of your icing. Because of the corn syrup, this royal icing isn’t going to form the same large, stiff peaks that you’d get when making other royal icing – that’s totally fine! This will work & taste great!! The icing consistency should feel kind of like runnier marshmallow cream. When you lift the mixer attachment and icing starts to drizzle back into the bowl, it should take about 8-10 seconds for that ribbon of icing to completely melt back into the bowl. This is where you might need to add a little bit more water - read the note on consistency below!

Note on the amount of water: I've noticed that when I make this icing during warmer weather months (and it's more humid outside), I rarely have to use more than the original 5 T of water in the icing. However, when it's colder & dryer and our heater is running, the icing is thicker and I need to use more water to thin it out a bit. Still start with that 5 T of water, and then slowly add from there if you need to thin it out a little bit.

Test the icing consistency: The icing should be thin enough to flow out of a piping bag, but not so thin that it'll run off the cookies. Testing is easy! Just take about a tablespoon of the icing, spoon it in a piping bag or Ziplock-type sandwich bag, cut a small tip out of the bag, and practice on a cookie. You should be able to outline the cookie without the icing running off, and you should be able to fill it in pretty easily. If the icing is too runny, you can add a little bit of powdered sugar - about a tablespoon at a time, mixing between additions - and repeat until it's thick enough. If it's too thick, you can add a little bit of water - about 1/2 tsp at a time, mixing between additions. (If you need to add additional powdered sugar or water, you just need to mix until everything is incorporated - just a few spins around the mixer. Then repeat that process if you need to add a little bit more of one or the other.)

Note: The icing in the mixing bowl will likely have air bubbles in it. I don't worry about it - the air bubbles usually go away when you add the icing to the piping bags and frost the cookies. You can always use the tip of your piping bag/icing bag tip to pop any small air bubbles that come up as you're decorating.

To color: use gel food coloring (I use Wilton brand), starting with just a small amount, in separate bowls & mixing with the desired amount of white icing. The icing starts to set pretty quickly, so you'll want to cover the main bowl with plastic wrap while you add color + smaller amounts of icing in the other bowls. Transfer to a piping bag soon after you mix in order to prevent the icing from getting too hard in the bowls (or just make sure to cover with plastic wrap).

To decorate: Add icing to piping bags or Ziplock sandwich bags, cut the tip out (start out with cutting a smaller tip - you can easily make it larger if you need to), and then use it to pipe an outline around your cookie, and then fill in the inside. You can use the tip to spread the icing around a little bit as you gently squeeze out more icing to fill in the shape. Or, simply drizzle some icing on the cookie for a "scribbled" look. You'll want to add sprinkles right after you ice each cookie, just because the icing does start to set on top pretty quickly. Check out this post for complete decorating details.

To dry: Allow cookies to set out overnight - just let them sit on a baking sheet on your counter. (Yes, they'll still taste great the next day!) Unless the icing is very thick, cookies should be dry enough to stack by the morning. If you plan to ship them or transport them in such a way that they'll shift around quite a bit, you may want to give them a few extra hours on top of that to set.

To freeze: Make sure icing is completely dry, and then place cookies in airtight container with wax paper between layers. Remove container from the freezer and allow to sit on the counter to thaw & come up to room temperature.