In a large bowl, combine the first 12 ingredients. Transfer to a greased 11x7-in. baking dish. Refrigerate, covered, 8 hours or overnight.
Remove oatmeal from refrigerator 30 minutes before baking. Preheat oven to 350°. Uncover and stir oatmeal; sprinkle with pecans. Bake, uncovered, 30-35 minutes or until a thermometer reads 160°. Serve warm with additional milk and brown sugar.