In a bowl, combine pears, cherries and lemon juice; set aside. In another bowl, combine vanilla, brown sugar, cornstarch and cinnamon. Sprinkle over pear mixture and gently toss to coat. Cover and refrigerate at least 1 hour or as long as overnight.
Place pear mixture in a greased 9-in. square baking dish. For topping, combine oats, brown sugar, flour, pecans, cinnamon and nutmeg in a bowl. Stir in butter. Sprinkle over pear mixture. Bake at 350° for 35-45 minutes or until filling is bubbly and topping golden brown. Serve warm with ice cream. Yield: 6 servings.