Combine egg whites (at room temperature), vinegar, salt, and cinnamon in a medium mixing bowl; beat until frothy. Gradually add sugar, 1 tablespoon at a time, beating until stiff peaks form and sugar dissolves. (Do not under beat this mixture.)
Spoon meringue mixture onto a baking sheet covered with unglazed brown paper. (Do not use recycled paper. ) Using back of spoon, shape meringue into a circle 8 inches in diameter; shape circle into a shell. (Sides of shell should be about 1 3/4 inches high.)
Bake at 275° for 1 hour. Turn oven off, and allow meringue to cool in oven 2 hours. (Do not open oven door.) Carefully remove Cinnamon Meringue Shell from brown paper. Use immediately, or store in an airtight container.