Start by lightly oiling and powdering an 8x8 pan with confectioner's sugar.
Pour 1/3 cup of water in the mixer's bowl.
Sprinkle 3 (1/4 oz) packets of unflavored gelatin into that water. After about 10 minutes it will be softened.
In a saucepan add 1/3 cup of water, 1 cup granulated sugar, a cu light corn syrup, and a pinch of salt.
Bring this up to 240 degrees over medium high heat.
With the mixer on low, carefully add the hot syrup to the gelatin. To that, add a tsp of vanilla.
With a lightly oiled spatula, spread the mixture into the 8x8 pan you prepped earlier. It will need to rest for at least an hour, until the mixture is cool and firm.
With a wet knive, you can loosen the sides and peel it out. Wet the knife often to avoid sticking. Cut it into squares.
To finish up, toss each marshmallow in confectioner's sugar, chocolate, coconut, etc- until completely covered.
Store in a singe layer or layers separated by wax paper. I learned the hard way the container I put them in collects moisture.
Oh, and don't let these dishes sit. They will turn into the stickiest mess ever. Hot water, stat!