Preheat the oven to 400 degrees F (200 degrees C). Line a large baking sheet with aluminum foil.
Combine squash, olive oil, brown sugar, sea salt, cinnamon, and cayenne pepper in a large bowl; toss until squash is evenly coated. Spread squash in an even layer onto the prepared baking sheet.
Roast in the preheated oven, turning midway through, until edges are lightly browned and centers are tender, 40 to 45 minutes. Transfer to a serving dish and garnish with nuts.
Roasted Butternut Squash with Brown Sugar · Dinner Match Lab | Dinner Match Lab