1. Brush a 9-by-13-inch glass baking dish with vegetable oil. Cut a piece of parchment or wax paper large enough to cover the bottom of the dish and to overhang the longer sides. Place the parchment in dish, brush with oil, and set dish aside.
2. Pour 3/4 cup cold water in the bowl of an electric mixer, and sprinkle gelatin on top. Let stand 5 minutes.
3. Place 3 cups granulated sugar, corn syrup, salt, and 3/4 cup water in a medium saucepan. Set saucepan over high heat, and bring to a boil. Insert a candy thermometer, and cook until mixture reaches soft-ball stage (238°), about 9 minutes.
4. Using the whisk attachment, beat hot syrup into gelatin on low speed. Gradually increasing speed to high, beat until mixture is very stiff, about 12 minutes. Beat in vanilla. Pour mixture into the prepared baking dish, and smooth the surface with an offset spatula. Set dish aside, uncovered, until marshmallow becomes firm, at least 3 hours or overnight.
5. The confectioners sugar is optional here. Place 1 cup confectioners sugar in a fine strainer, and sift onto a clean work surface. Invert large marshmallow onto the sugar-coated surface, and peel off the parchment paper. Lightly brush a sharp knife with vegetable oil, and cut marshmallow into 2-inch squares. Sift remaining 1/2 cup confectioners sugar into a small bowl, and roll marshmallows in sugar to coat. Set aside.
Just about any kind of dessert sprinkle can be used on the marshmallows. Additional flavorings (lemon extract is good) can be blended with the vanilla extract. This recipe is complements of Martha Stewart.
Smore's made with this recipe.
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