Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper or foil.

Peel and cube the sweet potatoes into 1 to 1.5-inch pieces.

Toss the sweet potato cubes with olive oil in a large bowl until well-coated.

Spread them evenly on the baking sheet and roast for 20 minutes, flipping halfway through.

Melt butter in a small saucepan over low heat. Stir in brown sugar, cinnamon, salt, and optional vanilla extract. Let it simmer for 2–3 minutes.

Remove sweet potatoes from the oven, drizzle with cinnamon butter glaze, and toss gently to coat.

Return sweet potatoes to the oven and roast for another 10–15 minutes.

Let cool slightly before serving and spoon remaining glaze on top.