Place the whole raw unpeeled sweet potatoes in a single layer on the bottom of the slow cooker. They should fit snugly; it’s okay if they touch but try not to stack them.
Sprinkle the brown sugar evenly over the tops of the sweet potatoes. Scatter the butter pieces over the sugar, then sprinkle the cinnamon over everything.
Brown sugar, butter, and cinnamon layered over sweet potatoes in a slow cooker
Cover the slow cooker with the lid and cook on LOW for 6 to 7 hours, or on HIGH for 3 to 4 hours, until the sweet potatoes are very tender when pierced with a fork and starting to slump and release juices.
Once cooked, carefully use tongs to gently squeeze each sweet potato to loosen the insides, then split them open lengthwise right in the slow cooker or on serving plates.
Stir the buttery brown sugar and cinnamon mixture in the bottom of the slow cooker to combine with the sweet potato juices, forming a simple sauce.
Cooked sweet potatoes split open with glossy sauce in the slow cooker
Spoon the warm sauce over the opened sweet potatoes and serve immediately, enjoying the soft flesh and edible skins together for a cozy, Earth Day–friendly dessert.
Variations & Tips
Swap the brown sugar for maple syrup or honey for a different kind of sweetness; just drizzle 1/4 cup over the potatoes before adding the butter and cinnamon.
For a slightly more indulgent version, add a splash (2 to 3 tablespoons) of heavy cream or canned coconut milk to the slow cooker in the last 30 minutes to create a richer sauce. If you like a little texture, sprinkle chopped pecans or walnuts over the sweet potatoes right before serving.
Served sweet potato dessert topped with yogurt and chopped nuts
To lean into the Earth Day theme, leave the skins on when you eat—most of the fiber and nutrients are there, and they get nice and soft in the slow cooker. You can also meal-prep these: cook a full batch, refrigerate, then reheat individual sweet potatoes in the microwave and top with yogurt, nut butter, or a bit of granola for a fast dessert or sweet breakfast.