Preheat your oven to 375°F (190°C). If you prefer, you can roast the sweet potatoes whole first and then cut them, but for speed, peel and cut them into 1-inch cubes.

Place the sweet potato cubes in a medium pot and cover with cold water. Add a pinch of salt, bring to a boil, then simmer for about 8–10 minutes until just tender but not falling apart. Drain and set aside. (Alternatively, toss with a little oil and roast for 20–25 minutes until tender.)

While the potatoes cook, make the glaze: In a small saucepan over medium heat, melt the butter. Stir in the brown sugar and maple syrup (or honey), and cook, stirring, until the sugar dissolves and the mixture becomes slightly syrupy—about 2–3 minutes. Remove from heat and stir in the vanilla, cinnamon, nutmeg, lemon or orange juice, and salt.

Transfer the drained sweet potatoes to a 9x13-inch baking dish (or a similarly sized ovenproof dish). Pour the warm glaze evenly over the potatoes, gently tossing with a spatula or spoon so the pieces are coated but not mashed.

Cover the dish with foil and bake in the preheated oven for 20 minutes to allow the flavors to meld and the glaze to thicken around the sweet potatoes.

Remove the foil and evenly scatter the mini marshmallows over the top. Return the dish to the oven, uncovered, and bake for another 5–8 minutes until the marshmallows have softened and begun to brown.

For a toasted, slightly caramelized finish, place the dish under the broiler on high for 1–2 minutes—watch carefully to prevent burning. Alternatively, use a kitchen torch to brown the marshmallows spots for more control.

Remove from oven and let the dish rest for 5 minutes so the glaze sets slightly. Sprinkle with chopped pecans if using, and serve warm.