Spray a 5-quart slow cooker with butter-flavored cooking spray and set aside.
In a large bowl, combine pie filling, pears, and almond extract. Pour into prepared slow cooker. Sprinkle cake mix over fruit mixture. Dot with butter. In a small bowl, combine oatmeal packet and almonds. Sprinkle over cake mixture.
Place 8 paper towels over slow cooker bowl and secure with lid. (This helps to trap steam.) Cook on LOW setting for 4 to 6 hours. Do not lift lid to check cake for the first 3 hours.
Serve warm with whipped topping.