Homemade Marshmallows

3 packages unflavored gelatin
1 1/2 cups white sugar
1/2 cup cold water
1 cup light corn syrup
1/4 teaspoon salt
1/2 cup water
1 tablespoon pure vanilla extract
confectioners' sugar, for dusting

Combine the gelatin and 1/2 c.
of cold water in the bowl of an electric mixer fitted with the whisk attachment and allow to sit while you make the syrup.
Combine the sugar, corn syrup, salt, and 1/2 c.
water in a small pan and cook over med.
heat until the sugar dissolves.
Raise the heat to high and cook until the syrup reaches 240 degrees on a candy thermometer.
Remove from heat.
With the mixer on low speed, slowly pour the sugar syrup into the dissolved gelatin.
Put the mixer on high speed and whip until the mixture is very thick, about 15 minutes.
Add the vanilla and mix thoroughly.
With a sieve, generously dust an 8 X 12 inch non-metal baking dish with confectioners' sugar.
Pour the marshmallow mix into the pan, smooth the top, and dust with more confectioners' sugar.
Allow to stand uncovered overnight until it dries out.
Turn the marshmallows onto a board and cut them into squares.
Dust them with more confectioners' sugar.