Homemade Marshmallow Spread

In a medium-sized saucepan combine the water, sugar and corn syrup (or honey). Stir gently to combine. Insert a candy thermometer set for 240°F and heat over medium-high flame. Do not stir the sugar water as it cooks or it will form crystals., When the sugar syrup begins to form large bubbles, and the thermometer reads about 225°F to 230°F, place the egg whites and cream of tartar in the bowl of your stand mixer and beat the whites to soft peaks. This should take about 3 to 4 minutes., By the time the whites are whipped, the sugar syrup should be at 240°F. Remove from the heat and with the mixer running, carefully pour the syrup in a thin, steady stream into the whites., The whites will deflate slightly at first, but as the sugar syrup becomes incorporated, they will thicken, turn white and begin to fluff up., Continue to whip the fluffy spread for 7 to 8 minutes, or until very thick and glossy. Add the vanilla and whip for another minute., Scoop the spread into an airtight container. Store for up to 2 weeks at room temperature. The spread can be re-whipped by hand if it becomes "flat."