1Spray 3 1/2- to 4-quart slow cooker with cooking spray. Place apples evenly in bottom.
2In medium bowl, stir flour, granulated sugar, baking soda, salt, ginger, cinnamon and nutmeg until well mixed. In small bowl, mix water, molasses and oil until well mixed. Stir into flour mixture just until moistened. Spread over apples in slow cooker. Sprinkle with brown sugar.
3In 2-cup microwavable measuring cup, mix apple cider and butter. Microwave uncovered on High 2 to 3 minutes or until butter is melted and mixture is boiling. Pour over mixture in slow cooker.
4Cover; cook on High heat setting 2 hours 15 minutes to 2 hours 45 minutes or until toothpick inserted in center comes out clean. Turn off slow cooker; uncover. Let stand 15 minutes. Serve warm.