This Oatmeal Cookie Sweet Potato Casserole has all the Fall flavors in a one-pan dish including cranberries, raisins, cinnamon, pecans and sweet potato. It’s the perfect sweet side to accompany all those savory Thanksgiving dishes!
Oatmeal Raisin Cranberry Cookie and Marshmallow Topping:
½cup1 stick PLUS 6 tablespoons butter, softened, I prefer really soft, room temperature butter
¾cupbrown sugar
½cupgranulated sugar
2large eggs
1teaspoonvanilla
1-1/2cupsall-purpose flour
1teaspoonbaking soda
1teaspoonground cinnamon
½teaspoonkosher salt
3cupsold-fashioned whole oats
1/2cupdried cranberries
1/4cuppecanschopped
110 ounce bag mini marshmallows
Sweet Potato Filling:
5cupsabout 5-6 large cooked sweet potatoes, mashed
butter for greasing 13” x 9” x 2” oven-safe baking pan
2large eggs
1teaspoonvanilla extract
½cupmilkcan substitute cream or half and half
4tablespoons½ stick butter
Optional: up to 1 cup of sugar *depending on sweetness of sweet potatoesyou can taste test the sweet potatoes after they are baked and cooled
Instructions
Preheat oven to 350 degrees. Bake sweet potatoes for 1 hour or until cooked and tender. When they are done, allow them to cool completely.
Grease a 13” x 9” x 2” oven-safe baking pan, set aside.
Oatmeal Cookie & Marshmallow Topping:
Note: All the ingredients, including the eggs, should be at room temperature before starting the oatmeal cookie topping. In a large mixing bowl, beat the softened butter, brown sugar, granulated sugar on medium speed until creamy. In a small mixing bowl, combine flour, baking soda, cinnamon and salt and mix well. Add combined dry ingredients incrementally to creamed butter mixture, mix well. Add 2 eggs and vanilla and mix well. Add oats, cranberries, raisins and chopped pecans, mix well.
Peel cooled sweet potatoes and measure exactly 5 cups mashed sweet potatoes. In a large mixing bowl, mix mashed sweet potatoes, 2 eggs, 1/2 cup milk, 4 tablespoons butter, 1 teaspoon vanilla, and sugar (optional depending on taste preference). Spread sweet potato mixture evenly in the greased 13" x 9" x 2" baking pan. Add mini-marshmallows in an even layer on top, press them down. Add oatmeal cookie dough in an even layer on top of the marshmallows. Alternately, you can reserve half of the mini-marshmallows to have on top of the cookie layer. Bake for 30 minutes at 350 degrees F on the middle rack. At 30 minutes check on the casserole and if you are concerned about the top browning too much, add a foil tent over the top. Bake for 10 minutes more for a total time of 40 mins. When the casserole is done, allow to cool for at least 10 minutes before serving. Enjoy!
Notes
To save time, you can make the oatmeal cookie topping and the mashed sweet potatoes ahead of time the day before.
When you are baking the sweet potatoes you can just bake them on the wire rack or on a foil-lined baking sheet if you don’t want any drips in the oven. Make sure you wash and stab the sweet potatoes with a fork before baking.
The baking time can really vary for the sweet potatoes because the varying size of sweet potatoes. I usually set the timer for 1 hour (at 350 degrees F) and poke a fork in them to test. The fork should go in and come out easily and if there's any resistance they need more time. You might have some smaller ones that are done and larger ones that need more time, so just leave the ones that need more time in and check periodically until fully cooked.
Make sure you measure the 5 cups of sweet potatoes and the other ingredients exactly because you will need the entire volume of the pan for this recipe. You can bake the casserole over a cookie sheet if you are concerned about drips.
The casserole's total baking time is 40 minutes but it's possible that it will be done at 30 minutes depending on preference. I add an extra 10 minutes, with an optional foil tent to get a really crispy oatmeal cookie crust you you might prefer something different. Make sure all the ingredients at every layer are evenly distributed to ensure even baking.