Prep and cook the sweet potatoes. Heat oven to 400°F (200°C). Pierce sweet potatoes several times with a fork, place on a foil-lined sheet, and roast 45–60 minutes, until very tender. Let cool slightly, then scoop flesh into a bowl. Reduce oven to 350°F (175°C).

Grease your bakeware. Lightly coat a 12-cup muffin tin or 8–10 ramekins with nonstick spray or butter. This helps the cups release cleanly.

Mash and season. Mash sweet potato flesh until smooth. Add 3 tablespoons melted butter, 1/3 cup milk, 2 eggs, 2–3 tablespoons maple syrup or brown sugar, 1 teaspoon vanilla, 1/2 teaspoon cinnamon, a pinch of nutmeg, and 1/2 teaspoon salt. Blend with a hand mixer or whisk until silky. Taste and adjust sweetness or salt.

Make the pecan streusel. In a small bowl, combine 1/2 cup chopped pecans, 1/4 cup flour, 2 tablespoons granulated sugar, 1/4 teaspoon cinnamon, and a pinch of salt. Cut in 2 tablespoons cold butter until crumbly. For gluten-free, use almond flour; for dairy-free, use coconut oil.

Portion the batter. Spoon sweet potato mixture into your prepared cups, filling each about 3/4 full. Tap the pan gently to settle the batter and smooth the tops with the back of a spoon.

Add toppings. Sprinkle each cup with a tablespoon of streusel. If you love the classic marshmallow finish, add 3–4 mini marshmallows on top, or save them for the last 5–7 minutes of baking to prevent over-browning.

Bake. Bake at 350°F (175°C) for 18–22 minutes for muffin tins or 22–28 minutes for ramekins. They’re done when the edges are set, the centers are slightly puffed, and a toothpick comes out with just a few moist crumbs.

Optional toast. For extra color, switch to a low broil for 30–60 seconds to toast the streusel or marshmallows. Watch closely to prevent burning.

Cool slightly and serve. Let the cups rest 5–10 minutes. Run a thin knife around muffin tin edges to release. Serve warm as a side dish or dessert.