Preheat oven to 400 degrees F. Lightly oil a baking sheet or coat with nonstick spray.
Place butternut squash in a single layer onto the prepared baking sheet. Add olive oil, maple syrup, brown sugar, cinnamon and nutmeg. Gently toss to combine.
Place into oven and bake for 25-30 minutes, turning once, until tender.* Add pecans during the last 10 minutes of cooking time.
Serve immediately, garnished with rosemary, if desired.
Notes
*Baking time may need to be adjusted depending on the thickness of the butternut squash.