Line a baking sheet with parchment paper, then dust it with an even layer of powdered sugar.

Put 1/2-cup of cold water into your mixer bowl.

Add the gelatin and let it sit to proof while you do the next step.

Combine the granulated sugar, salt, corn syrup and remaining water in a medium saucepan with a lid.

Heat the mixture over medium heat, stirring constantly, until it comes to a boil.

Put the cover on the pot and turn the heat down slightly. Let it boil with the lid on for about 2 minutes. This step cooks down any sugar crystals on the side of the pot.

Uncover the pot and turn the heat back up to medium.

Put a candy thermometer in the pot and boil the mixture until it reaches 240 degrees, which will usually take about 10 minutes.

Fit your mixer with the whisk attachment and turn it on medium speed.

Slowly pour the sugar solution down the side of the mixer bowl into the gelatin while the mixer works at medium speed to combine the ingredients.

Once the sugar solution is fully poured in the bowl, turn the mixer speed to high and let it work until the solution is doubled in size and stiffened, about twelve minutes.

Add the vanilla extract and beat for another two minutes.

Scoop the mixture into a piping bag and pipe it onto the parchment paper or spread it evenly into the pan.

Let the marshmallows air dry for twelve hours.

Dust the top of the marshmallow layer with powdered sugar, then use a pizza cutter or cookie cutters to cut shapes.

Dust piped marshmallows with powdered sugar lightly so that they don't stick to each other.

Store finished marshmallows in an airtight container for up to two weeks.