Sweet potato casserole with oatmeal and marshmallows

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Oatmeal Cookie Marshmallow Sweet Potato Casserole: I am a contributor to Amanda’s Cookin’ and this recipe first appeared on there as Oatmeal Cookie Sweet Potato Casserole.

This Oatmeal Cookie Marshmallow 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!

Estimated reading time: 6 minutes

Oatmeal Cookie Marshmallow Sweet Potato Casserole is the dish that everyone is going to look forward to because it’s like having a dessert during dinner!

It has a classic sweet potato casserole, with a layer of marshmallows and then topped with oatmeal raisin cranberry cookie crust!

This recipe is partly inspired by my Oatmeal Raisin Cranberry Cookies recipe.

I added 1/4 cup chopped pecans which goes perfectly with the oatmeal cookie crust and sweet potato.

If you prefer, you can substitute the same amount in walnuts or skip the nuts altogether.

I found that the addition of pecans added a nice, subtle, nutty crunch to the casserole.

Ingredients

Oatmeal Raisin Cranberry Cookie and Marshmallow Topping

• ½ cup (1 stick) PLUS 6 tablespoons butter, softened, I prefer really soft, room temperature butter
• ¾ cup brown sugar
• ½ cup granulated sugar
• 2 large eggs
• 1 teaspoon vanilla
• 1-1/2 cups all-purpose flour
• 1 teaspoon baking soda
• 1 teaspoon ground cinnamon
• ½ teaspoon kosher salt
• 3 cups old-fashioned whole oats
• 1/4 cup pecans, chopped
• 1 (10 ounces) bag mini marshmallows (if you only have regular-size marshmallows on hand, cut them down to mini-marshmallow size)

Sweet Potato Casserole Filling

• 5 cups (about 6 large) cooked sweet potatoes
• butter for greasing 13” x 9” x 2” oven-safe baking pan
• 2 large eggs
• 1 teaspoon vanilla extract
• ½ milk (can substitute cream or half and half)
• 4 tablespoons (½ stick) butter
• Optional: up to 1 cup of sugar *depending on the sweetness of sweet potatoes, if the sweet potatoes are really sweet, then I usually skip the sugar.

Tips for Success for Oatmeal Cookie Marshmallow Sweet Potato Casserole

1. To save time, you can make the oatmeal cookie topping and the mashed sweet potatoes ahead of time the day before.
2. 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.
3. The baking time can really vary for the sweet potatoes because of 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.
4. 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.
5. 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.

Kitchen Tools Needed for Oatmeal Cookie Marshmallow Sweet Potato Casserole

1. 13″ x 9″ x 2″ oven-safe baking pan or better a 13″ x 9″ x 3″ baking pan – I have a 13″ x 9″ x 2″ pan and with all the ingredients it does get a little overfilled above the upper edge but as long as all the ingredients have been measured properly and evenly spread, everything should fit. You can always put a cookie sheet under the baking pan if you are concerned about drips.
2. Electric hand mixer or a stand mixer – I used my hand mixer and that had sufficient power for mixing both the oatmeal cookie crust and the sweet potato casserole filling.
3. large mixing bowl
4. baking spatula

Web Story

The aroma in your house is amazing while this Oatmeal Cookie Marshmallow Sweet Potato Casserole is baking in the oven 🙂

I hope you enjoy this sweet and delicious casserole as much as my family and I do! Enjoy!

Other Potato Recipes You Might Also Like

• Perfect Sage Thyme Butter Whipped Potatoes
• Homemade Mashed Potatoes
• Roasted Rosemary Potatoes
• Herbes de Provence Roasted Sweet Potatoes
• Red Potato Salad with Dill
• Potato Pancakes (GF) #FoodieMamas
• Classic Homemade Tater Tot Casserole

Recipe Attribution

This Oatmeal Cookie Marshmallow Sweet Potato Casserole recipe is partly inspired by Southern Sweet Potato Casserole by Add A Pinch and Oatmeal Raisin Cranberry Cookies by Life’s Little Sweets

Our Other Recipes and Posts

• Almond Butter Oatmeal Energy Bites on SoFabFood
• Green Bean Turkey Casserole
• Apple Carrot Raisin Chicken Salad
• Classic Homemade Tater Tot Casserole
• Sweet Potato Kale Lentil Soup
• If you like this Oatmeal Cookie Marshmallow Sweet Potato Casserole recipe, Check out Dinner, Savory & Vegan categories

What’s your favorite Fall/Thanksgiving/Christmas side dish? Let me know in the comments below! Have a sweet day!

Ingredients

Topping

• ½ cup (1 stick) PLUS 6 tablespoons butter, softened, I prefer really soft, room temperature butter
• ¾ cup brown sugar
• ½ cup granulated sugar
• 2 large eggs
• 1 teaspoon vanilla
• 1-1/2 cups all-purpose flour
• 1 teaspoon baking soda
• 1 teaspoon ground cinnamon
• ½ teaspoon kosher salt
• 3 cups old-fashioned whole oats
• 1/4 cup pecans, chopped
• 1 (10 ounces) bag mini marshmallows (if you only have regular-size marshmallows on hand, cut them down to mini-marshmallow size)

Filling

• 5 cups (about 6 large) cooked sweet potatoes
• butter for greasing 13” x 9” x 2” oven-safe baking pan
• 2 large eggs
• 1 teaspoon vanilla extract
• ½ milk, (can substitute cream or half and half)
• 4 tablespoons (½ stick) butter
• Optional: up to 1 cup of sugar *depending on the sweetness of sweet potatoes, if the sweet potatoes are really sweet, then I usually skip the sugar.

Instructions

1. 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.
2. Grease a 13” x 9” x 2” oven-safe baking pan, set aside.
3. Oatmeal Cookie & Marshmallow Topping:
4. 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.
5. 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 it to cool for at least 10 minutes before serving. Enjoy!

Nutrition Information:

Yield: 13 Serving Size: 1
Amount Per Serving: Calories: 592Total Fat: 21gSaturated Fat: 12gTrans Fat: 1gUnsaturated Fat: 8gCholesterol: 105mgSodium: 372mgCarbohydrates: 69gFiber: 3gSugar: 43gProtein: 6g

Please note that the Calculated Nutrition is an estimate at best.

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Sara is an architectural designer turned work-at-home Mom. She lives in New Jersey by way of New England and New York, with her husband and 3 kids under 8. She loves design, being creative, and spending time with family and friends. She loves checking out local businesses and eats and being apart of the local farm to table community.

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