Preheat oven to 225º.
Cover 2 large baking sheets with parchment paper, and secure paper with masking tape.
Scrape seeds from vanilla bean. Reserve vanilla bean for another use.
Place egg whites and cream of tartar in a large bowl; beat with a mixer at medium speed until soft peaks form. Increase speed to high, and gradually add granulated sugar and then powdered sugar, 1 tablespoon at a time, beating until stiff peaks form. Add vanilla seeds and extract; beat just until blended.
Spoon batter into a pastry bag fitted with a large star tip. Pipe 60 mounds onto prepared baking sheets.
Bake at 225º for 1 1/2 hours. Turn oven off; cool meringues in closed oven 1 1/2 hours or until dry. Carefully remove the meringues from paper.