Boil sweet potatoes for about 20-30 minutes until fork tender. Let cool.
Spray a 9x13 inch pan with non stick cooking spray.
After the sweet potatoes are cool, peel of skins and slice into 1 inch spears. Lay half of them in the pan.
Cut up 1 ½ tablespoons of butter into small pieces and spread all over the sliced sweet potatoes.
Then drizzle ⅛ cup of karo syrup over all of the sweet potatoes. Then sprinkle ¼ cup of brown sugar over the top.
Repeat layers - add more sweet potatoes, then top with the rest of the butter, karo syrup, and brown sugar.
Cook in oven until heated through and butter is melted. About 30 minutes.
Remove from oven and cover the top with marshmallows. Return to oven cook until marshmallows are golden brown.
Notes
This can also be made ahead of time and stored in the fridge. Don’t cook until you are about ready to eat. ( Cook until heated through and then add marshmallows.)It’s best to eat this recipe soon after taking it out of the oven. We usually make the sweet potatoes the night before, then the afternoon of thanksgiving, we cook it right before we eat. Cook until heated through and then add marshmallows.We recommend not adding the marshmallows until after it is cooked a little, to avoid burning. If you store them overnight, they will get soggy with all the gooey goodness in the pan.