In a small bowl, whisk together ½ cup melted butter, ¼ cup brown sugar, 2 tsp ground cinnamon, and 1 tsp vanilla extract until combined.
Place 4 lbs peeled and diced sweet potatoes into a 4–6 quart crock pot.
Pour the butter mixture over the sweet potatoes and toss until the potatoes are evenly coated.
Sprinkle ½ cup chopped pecans evenly over the sweet potatoes.
Cover and cook on Low for 7–8 hours or on High for 3–4 hours, until the sweet potatoes are tender.
During the last 10–15 minutes of cooking, sprinkle 1½ cups miniature marshmallows evenly over the top.
Cover and continue cooking until the marshmallows are soft and lightly melted.
Serve immediately and enjoy.
Video
Notes
Crock Pot Sweet Potato Casserole Tips
If you have a lot of other things to cook, it is helpful to do the prep work in advance. By going ahead and peeling and dicing the potatoes.
Make sure to peel the sweet potatoes entirely. The skin adds a toughness to the casserole so make sure to remove all the skin will peeling.
Dice the sweet potatoes into even pieces. This will ensure that the sweet potatoes cook evenly. Try to get them in as even as sizes as possible.
Leave the lid off at the end of cooking time. - I do remove the lid from the crock pot for the last 15-20 minutes so any extra moisture will cook off.
Variation Ideas
Chopped Nuts - The pecan topping in the recipe is optional. It will also be good with any of your favorite type of nuts. Walnuts or almonds would be great too.
Marshmallows - We used mini marshmallows but you can use regular size marshmallows as well. I think either one would be delicious.
Mashed Sweet Potatoes - You can mash the sweet potatoes. This recipe leaves the potatoes diced. However, if you prefer you can use a potato masher and mash them.
Add Sweetness - If you like things sweeter, add a little bit of maple syrup or honey to the sweet potatoes before cooking.