Preheat the oven to 375°F (190°C). Lightly coat a sheet pan with cooking spray so the sweet potatoes bake cleanly without sticking.
Peel the sweet potatoes, then dice them into uniform 1-inch pieces to encourage even cooking and a tender finished texture.
In a small mixing bowl, whisk together the melted butter, maple syrup, ground cinnamon, and salt until the mixture is smooth and well combined.
Arrange the sweet potato cubes in a single layer on the prepared sheet pan. Pour the maple-cinnamon butter mixture over the potatoes, then toss thoroughly with a spoon or clean hands until every piece is evenly coated.
Bake for 35 minutes, stirring once halfway through the baking time to promote even roasting and light caramelization.
Remove the sweet potatoes from the oven once they are tender and slightly caramelized. Serve immediately while warm.