Instructions: In a mixing bowl, mix the gelatin with half of the raspberry puree. Give it ten minutes to bloom. The remaining 1/2 cup of raspberry puree, corn syrup, granulated sugar, and salt should all be combined in a saucepan. Stirring constantly, heat over medium heat until the sugar dissolves. Without stirring, bring the mixture to a boil and allow it to reach the soft-ball stage 240F on a candy thermometer. Slowly pour the hot raspberry syrup into the bloomed gelatin mixture using a stand mixer set on low speed. Turn the speed up to high and whip for ten to fifteen minutes, or until the mixture gets very thick and fluffy. Finally, add the vanilla extract and continue whipping. In a bowl, whisk together cornstarch and confectioners' sugar while the marshmallow mixture is whipping. Coat the bottom and sides of a 9 x 13-inch baking dish with grease and sprinkle with the sugar-cornstarch mixture. Pour the marshmallow mixture into the baking dish that has been prepared once it is ready. Using a spatula, smooth the top and sprinkle additional sugar-cornstarch mixture on it. Until the marshmallows are set and no longer sticky, let them sit uncovered at room temperature for at least four hours or overnight. Once the marshmallows are set, cut them into the desired shapes with a knife or cookie cutters. To keep the cut sides from sticking, dust them with extra of the sugar-cornstarch mixture. The raspberry marshmallows can be kept for up to two weeks in an airtight container layered between parchment paper sheets.
