In 12-inch nonstick skillet, cook sausage over medium-high heat 5 to 7 minutes, stirring occasionally, until no longer pink. With slotted spoon, remove sausage from skillet to bowl. Set aside.
Add butter to pan drippings in skillet; cook over medium heat until butter is melted. Add flour; cook about 1 minute, stirring constantly with whisk, until no lumps remain. Add milk; cook 2 to 3 minutes, stirring constantly, until mixture is thickened. Remove from heat. Stir in soup, fennel seed and sausage until combined.
Spray 3 1/2- to 4-quart slow cooker with cooking spray. Separate each can of dough into 10 biscuits; cut each biscuit into quarters. Arrange biscuit pieces in bottom and up side of slow cooker. Pour sausage mixture into slow cooker. Place triple layer of paper towels on top of ingredients in slow cooker.
Cover; cook on Low heat setting 3 hours 30 minutes to 4 hours 30 minutes or until biscuits are cooked through and deep golden brown around edges. Spoon into bowls to serve.