Combine first 7 ingredients in a bowl; stir well, and set aside. Place parchment paper over a large baking sheet. Draw 6 (4-inch) circles on parchment paper. Turn parchment paper over, and secure with masking tape.
Beat egg whites and cream of tartar with a mixer at high speed until foamy. Add extract; beat well. Gradually add 2/3 cup sugar, 1 tablespoon at a time, beating until stiff peaks form. Fold coconut into egg white mixture. Divide egg white mixture evenly among the 6 drawn circles. Shape meringues into nests with 1-inch sides using the back of a spoon.
Bake at 250° for 1 hour or until dry. Turn oven off; cool meringue nests in closed oven at least 4 hours. Carefully remove meringue nests from paper.
Spoon 1/4 cup ice cream, if desired, into each meringue nest, and top with about 2/3 cup fruit mixture. Garnish with mint sprigs, if desired.
Make a template to ensure your pavlovas come out looking perfect. Trace circles onto parchment paper as a guide for shaping the nests; a standard oatmeal can is the perfect size. Turn the paper (and the pencil markings) over before securing to the baking sheet.