1. Arrange pears, cut sides down, in a 13-x 9-inch pan. Sprinkle with lemon juice and sugar; drizzle evenly with melted spread.
2. Bake at 375° for 25 to 40 minutes or just until tender. Remove pears from pan, reserving juices in pan; keep pears warm.
3. Whisk together pan juices, 1/4 cup of water, and vanilla in 13- x 9-inch pan. Stirring to loosen particles from bottom of pan. Cook over medium heat, stirring constantly, 6 minutes or until sauce is thickened and golden. Serve sauce over pears with frozen yogurt. Garnish, if desired.