PREHEAT oven to 350° F. Spray 2-quart casserole dish with cooking spray.
PLACE potatoes in large saucepan; cover with water. Bring to a boil. Reduce heat to medium-low; cook for 15 to 20 minutes or until fork tender. Drain; return to saucepan or mixing bowl and cool for 5 minutes.
ADD granulated sugar, Coffee-mate, 3 tablespoons melted butter and salt to saucepan with sweet potatoes. With handheld mixer, beat until smooth. Add eggs; beat until incorporated. Pour mixture into prepared casserole dish.
COMBINE nuts, brown sugar and flour in medium bowl; stir in 1 tablespoon butter. Sprinkle over top of casserole.
BAKE for 25 to 30 minutes or until heated through and bubbly. Remove from oven.
PREHEAT broiler. Broil casserole for 30 seconds or until top starts to brown. Cool slightly before serving.
Cook’s Tip: To toast hazelnuts, place in a dry skillet over medium heat, shaking pan or stirring occasionally, for 10 minutes or until fragrant. While nuts are still warm, wrap them in a kitchen towel and rub vigorously to remove the skins. It’s okay if a few skins cling to the nuts.