Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper.
- Toss the diced butternut squash with olive oil, salt, and pepper. Spread it in a single layer on the prepared baking sheet.
- Roast the squash for 20-25 minutes, flipping halfway through, until tender and golden brown.
- While the squash is roasting, make the balsamic glaze. In a small saucepan, combine balsamic vinegar and honey (or maple syrup). Bring to a simmer over medium heat and cook for 5-7 minutes, until the vinegar reduces by half and thickens to a syrupy consistency.
- Once the squash is roasted and slightly cooled, assemble the salad. In a large bowl or serving platter, layer the roasted squash, mozzarella balls, and fresh basil leaves.
- Drizzle the olive oil over the salad, followed by the balsamic glaze.
- Toss gently to combine and serve immediately.