- In a bowl, place the egg whites, cream of tartar and salt. Set aside.
- In a small saucepan, bring the sugar, corn syrup and water to a boil. Let simmer until a candy thermometer reads 240°F (116°C). Remove from the heat.
- Beat the egg white mixture with an electric mixer on medium speed until frothy. Drizzle the hot syrup onto the egg whites, avoiding the mixer’s beaters. Beat continuously until stiff peaks form.
- Transfer to jars. The spread will keep for 1 week in the refrigerator.
Use this marshmallow spread to frost your favourite vanilla cake, smear on toast or enjoy it straight from the jar!