Preheat oven to 400 degrees F. Line a 2-quart rectangular baking dish with Reynolds Wrap(R) Pan Lining Paper, parchment side up. No need to grease dish.
Add parsnips and/or carrots to a large microwave-safe bowl. Add 1/4 cup water and cover with wax paper. Microwave on high for 5 minutes. Uncover and add sweet potatoes. Cover and microwave 15 minutes more or until tender, stirring once. Drain and return vegetables to bowl.
Pour broth and cream into the bowl with vegetables. Use a potato masher to mash to desired consistency. Stir in 3 tablespoons butter and 1/2 teaspoon salt. Transfer to prepared baking dish.
Combine brown sugar, flour, rosemary, and 1/4 teaspoon salt in a medium bowl. Using a pastry blender, two forks, or your fingers, cut in 2 tablespoons butter until mixture resembles coarse crumbs. Stir in pecans and maple syrup and sprinkle over sweet potato-mixture.
Bake 20 to 25 minutes or until pecan mixture is just starting to brown.
Nothing says the holidays like a delicious sweet potato casserole! You can make it easy to serve and even easier to clean up by using pan lining paper to line the dish (parchment side up) before baking. Once you're done, just crumple up the paper and toss it in the trash. How's that for a hassle-free holiday?