Step 1

Add sweet potato pieces to large stockpot or dutch oven and cover with water.  Add a pinch of salt and bring to a boil.  Once boiling, reduce heat and cook at a high simmer for 12-15 minutes, until extremely fork tender.  Drain in a colander, shake gently to remove excess liquid, then transfer cooked potatoes back to the pot you boiled them in.  Let them sit for a few minutes, and this will help remove any excess liquid in the potatoes.

Step 2

While potatoes are boiling, preheat oven to 350 F degrees.  Spray a 3qt baking dish (like a 9x13 pan) with non-stick cooking spray.  Set aside.

Step 3

Transfer potatoes to a large mixing bowl.  Add brown sugar, granulated sugar, half and half, melted butter, maple syrup, salt, vanilla, cinnamon, nutmeg, cloves and eggs.  Beat with a hand mixer until fluffy and smooth.  Small lumps are okay.

Step 4

Transfer potato filling to prepared baking dish and set aside.

Step 5

To a food processor, add pecans and vanilla extract, pulsing a few times, until pecans are evenly chopped.  Add flour, brown sugar, cinnamon, nutmeg, cloves, and cold cubed butter.  Pulse several times, until crumble mixture looks like it has pea-sized crumbs.

Step 6

** If you don't have a food processor, use a knife to chop pecans, then add remaining ingredients and use a pastry cutter, two forks, or even your hands, to mix until mixture has pea-sized crumbs. **

Step 7

Spread crumble topping over sweet potato mixture in an even layer.  Bake casserole in preheated oven for 30 - 40 minutes, until golden brown.

Step 8

Remove baked casserole from oven and spread mini marshmallows over the top in a single even layer.  Bake for 5-10 minutes, then if desired, broil to toast the marshmallows.  Broil only for a minute or two, they'll burn quickly!