Slow Cooker Sweet Potato Casserole
This is the sweet, spiced side that some families treat as a second dessert. The sweet potatoes cook in the slow cooker until soft enough to mash with butter and maple syrup, then get a crunchy brown sugar pecan topping and a quick turn under the broiler to toast the marshmallows.
By Maya Ellison
Published

- Prep Time
- 20 mins
- Cook Time
- 3 hrs 35 mins
- Total Time
- 3 hrs 55 mins
- Servings
- 10 servings
How do you make Slow Cooker Sweet Potato Casserole?
To make sweet potato casserole in a slow cooker, cook 1.8 kg (4 lb) peeled, cubed sweet potatoes with butter and a splash of water on HIGH for 3-4 hours, until very soft. Mash with maple syrup, cinnamon, vanilla and salt and spoon into a baking dish. Top with brown sugar pecans and mini marshmallows and broil for 1-2 minutes, until golden.
- Total time
- 3 hrs 55 mins
- Calories
- 350 per serving
- Protein
- 4 g
- Yield
- 10 servings
- Difficulty
- Easy
- Method
- Slow cooking
Ingredients
Sweet potatoes
Pecan topping
Equipment
Slow cooker (5-6 L) · Potato masher · Small skillet · Parchment paper · Broiler-safe baking dish (23 x 33 cm / 9 x 13 inch)
Quick Directions
Slow cook the sweet potatoes
Put the sweet potatoes, butter and water in the slow cooker.
Make the pecan topping
Melt the butter in a small skillet over medium heat.
Mash and season
Mash the sweet potatoes in the slow cooker with the maple syrup, cinnamon, nutmeg, vanilla and salt until smooth.
Top and broil
Top with pecans and marshmallows and broil for 1-2 minutes.
Step-by-Step Instructions
Follow these detailed steps to make the perfect slow cooker sweet potato casserole.
Slow cook the sweet potatoes
Put the sweet potatoes, butter and water in the slow cooker. Cover and cook on HIGH for 3-4 hours or on LOW for 6-7 hours, until the sweet potatoes are very soft.
Make the pecan topping
Melt the butter in a small skillet over medium heat. Add the pecans, brown sugar and salt and stir for 3-4 minutes, until the sugar melts and coats the nuts. Spread them on parchment to cool; they crisp up as they cool.
Mash and season
Mash the sweet potatoes in the slow cooker with the maple syrup, cinnamon, nutmeg, vanilla and salt until smooth. Taste and adjust. You can hold the mash on WARM for up to 2 hours at this point.
Top and broil
Heat the broiler (oven grill) with a rack in the middle of the oven. Spoon the hot mash into the baking dish, scatter over the pecans and then the marshmallows. Broil for 1-2 minutes, watching the whole time, until the marshmallows are golden; they go from toasted to burnt in seconds. Serve hot.
Recipe Tips
- Broil the casserole while the turkey rests, when the oven is free.
- Most marshmallows contain gelatin. For a vegetarian casserole, use gelatin-free marshmallows or skip them and double the pecans.
- If you avoid gluten, check the marshmallow label for a gluten-free claim.
- Most slow cooker inserts can't go under the broiler, which is why the mash moves to a baking dish. Check your manufacturer's instructions.
Variations
- Skip the marshmallows for a pecan-only topping.
- Swap the maple syrup for 50 g (1/4 cup) packed brown sugar.
- Add the zest of 1 orange to the mash for a brighter flavour.
Nutrition (per serving)
| Calories | 350 |
|---|---|
| Protein | 4 g |
| Carbs | 55 g |
| Fat | 13 g |
| Saturated fat | 6 g |
| Fibre | 5 g |
| Sugar | 30 g |
| Sodium | 260 mg |
Estimated from the listed ingredients; values vary by brand.
Related Recipes
Storing & Reheating
- Fridge
- Keep the mash and pecan topping separately in airtight containers for up to 4 days.
- Freezer
- Freeze the plain mash for up to 3 months. Add the toppings after reheating.
- Reheat
- Reheat the mash covered at 175°C (350°F) for 25-30 minutes, or in the microwave, until steaming hot, then top and broil.
Slow Cooker Sweet Potato Casserole FAQs
Can I make sweet potato casserole ahead?
Yes. Cook and mash the sweet potatoes up to 2 days ahead and make the pecan topping up to 3 days ahead. Reheat the mash until steaming hot, then add the toppings and broil.
Can I make it without marshmallows?
Yes. Use the pecan topping on its own, or double it. It's sweet and crunchy without the marshmallows.
Are marshmallows vegetarian?
Most are not, because they're made with gelatin. Look for gelatin-free or vegan marshmallows if you're cooking for vegetarians.
Can I put the slow cooker insert under the broiler?
Most ceramic inserts aren't made for direct broiler heat, so check your manual. Spooning the mash into a broiler-safe baking dish takes a minute and is always safe.
Disclaimer
- Nutrition information is an estimate based on the listed ingredients. It changes with the brands, portion sizes and swaps you use.
- Read ingredient labels for allergens and for diet claims such as gluten-free or vegan. Products and their ingredients can change.
- Cooking times are a guide, since ovens, air fryers and slow cookers all run differently. Use a food thermometer and cook meat, poultry and fish to the safe internal temperatures in government food safety guidance.
- This recipe is general information, not medical or nutrition advice. If you have an allergy, a health condition or a special diet, check with a qualified health professional.







