In a large bowl, combine cake mix and oats; set aside 1/2 cup for topping. Add the butter, honey and water to the remaining cake mixture. Press onto the bottom of a 13x9-in. baking pan coated with cooking spray.
For filling, in a large bowl, beat the pumpkin, cream cheese, milk, brown sugar, maple syrup, cinnamon, vanilla, allspice and cloves until blended. Add egg and egg white; beat on low speed just until combined. Pour over crust. In a small bowl, combine the walnuts, butter and reserved cake mixture; sprinkle over filling.
Bake at 350° for 30-35 minutes or until set and edges are lightly browned. Cool on a wire rack. Cut into bars. Yield: 2 dozen.