MARSHMALLOW SQUARES, HOMEMADE

Oil bottom and sides of 13x9x2 inch pan and dust with confectioner’s sugar lightly.
In mixer bowl spring gelatin over 1/2 cup cold water and let soften. In heavy bottom saucepan cook granulated sugar and corn syrup and remaining 1/2 cup water and salt over low heat, stirring with wooden spoon until sugar dissolves. Increase heat to moderate and boil mixture without stirring until it reaches 240 on a thermometer (about 12 minutes). Remove syrup from heat and pour into gelatin mixer bowl and stir. Beat with mixer on high speed until white thick and nearly tripled in volume, about 6 – 10 minutes.  In clean dry separate bowl beat the egg whites until they are just holding stiff peaks. Add vanilla and beat into sugar mixture until just combined. Pour into baking pan. Spread evenly and sift 1/4 cup confectioners sugar evenly over top. Chill uncovered at least 3 hours or over night. Run a knife around edges of pan and invert onto a large cutting board. With large knife coated with oil, trim sides and cut into desired sized cubes. Roll each into powdered sugar and serve. Or store in air-tight container until needed; or up to one week at room temperature.