Instructions: Place the gelatin and 1/4 cup of water in a mixing bowl. Give it five to ten minutes to bloom. Combine the corn syrup, granulated sugar, and 1/4 cup water in a saucepan. Using a candy thermometer, heat it over medium-high heat until it reaches 240F 115C. After carefully adding the heated sugar syrup to the gelatin that has bloomed, whisk on low speed until the mixture thickens and begins to cool. To the mixture, add a few drops of yellow food coloring if desired and lemon sherbet powder. Whisk continuously until everything is combined. To keep food from sticking, grease a square pan and sprinkle it with powdered sugar. Using a spatula, level the top of the marshmallow mixture once it has been poured into the prepared pan. Allow it to settle for four to six hours, or over night, at room temperature. Once set, place the marshmallow slab onto a cutting board dusted with powdered sugar. Cut the marshmallows into the desired shapes, or into squares. To keep it from sticking, dust each piece with extra powdered sugar. You can now savor your Lemon Sherbet Marshmallows! For up to a week, keep them in an airtight container.