Preheat oven to 250°F. Line 2 baking sheets with parchment paper.
In a bowl using an electric mixer, beat egg whites, cream of tartar, and vanilla extract on high speed until foamy.
Add Splenda Sugar Blend 1 tablespoon at a time, beating until sweetener dissolves and stiff peaks form.
Spoon heaping tablespoons of mixture onto baking sheets.
Bake 1 hour and 15 minutes; turn oven off. (If meringues begin to brown, reduce oven temperature to 225 degrees.) Let meringues stand in oven, with door closed and oven light on, for 8 hours or overnight.