Beat egg whites at medium speed with an electric mixer until foamy; add cream of tartar and almond extract, beating until blended. Gradually add sugar, beating until stiff peaks form and sugar dissolves.
Pipe or spread mixture into small 2-inch cookie shapes or other desired shapes onto a parchment paper-lined baking sheet.
Bake at 200° for 2 hours. Turn oven off; let stand in closed oven with light on 8 hours.