Thaw the pastry sheets at room temperature. Tear off a 26-inch piece of 18-inch-wide heavy foil. Wrap a 12-inch pizza pan in the foil, completely enclosing it. Grease the inside of the foil-lined pizza pan; set side.

For pizza crust, unfold the pastry sheet on a lightly floured surface. Roll gently to flatten creases (you should have a 10-1/2-inch square). Cut a 10-inch circle from pastry (discard scraps). Place pastry circle on prepared pan. Prick pastry with a fork; set aside.

For topping: In a small bowl, combine brown sugar, cornstarch and cinnamon. In a large skillet, melt butter over medium heat. Stir in sugar mixture. Add apples. Cook about 3 minutes or until mixture is bubbly and sugar is dissolved, stirring occasionally. Remove from heat. Spoon apple mixture over pastry.

For a charcoal grill, arrange hot coals around edge of grill. Test for medium-hot heat over center of grill. Place pizza pan on rack in the center of grill. Cover; grill for about 30 minutes or until apples are tender and pastry is puffed and golden brown. (For a gas grill, preheat grill. Reduce heat to medium-hot. Adjust for indirect cooking. Place pizza pan on grill rack. Grill as above.) Remove from grill; let stand for 10 minutes.

Transfer pizza to a cutting board; cut into 6 wedges. Top each with a scoop of ice cream. If you like, drizzle with caramel ice cream topping. Serve immediately. Makes one 10-inch pizza (6 servings).