-
Sprinkle all the gelatin over 1/2 cup water in the bowl of the stand mixture and let it hydrate.
-
In a medium saucepan over medium heat, dissolve 12 oz granular sugar in 1/2 cup water.
-
Add the syrup and salt and increase the heat and put in the candy thermometer. Stir constantly until the syrup mixture reaches 240ºF. Remove from heat.
-
Let the syrup cool slightly and very slowly and very carefully pour it into the dissolved hydrated gelatin. Turn the stand mixer on low.
-
Once all the syrup is in, increase the speed to high for 15 minutes until it is thick and white.
-
Add vanilla extract and vanilla seeds and mix thoroughly.
-
Spray baking sheet with nonstick spray. Sift together cornstarch and powdered sugar and heavily coat entire baking sheet.
-
Spread marshmallow mixture onto baking sheet. Smooth surface with the back of a wet spatula.
-
Dust the top with more powdered sugar and refrigerate over night un covered.
-
On a surface dusted with powdered sugar and cornstarch, invert the baking sheet onto the surface. Marshmallows should come out easily.
-
Use a sharp knife dusted with cornstarch or a pizza cutter to cut marshmallow into squares.