Smashed Spiced Sweet Potatoes

4 lbs sweet potatoes (or yams) (4-5 lg)
2 Tbsp butter
2 Tbsp maple syrup
1 Tbsp chili powder
2 tsp ground cumin
1 tsp ground ginger
1 tsp salt
1/2 tsp ground pepper

Pierce each potato in several places with fork. Place directly on oven rack and roast until soft in a 350 oven (about 1 hr). Let cool enough to handle, about 10 min. Slip off the skins, cut potatoes into rounds and transfer to a large bowl. Add butter. Smash the potatoes with potato masher or fork until fluffy, but some lumps remain. Add syrup and spices. Stir to combine and enjoy.