1. Prepare your oven and baking sheet: Start by preheating your oven to 400 F (200 C). Line a large baking sheet with parchment paper. This step is crucial for easy cleanup and helps prevent the vegetables from sticking, especially with the sticky maple syrup.

2. Chop the vegetables: Peel the butternut squash, scoop out the seeds, and cut it into uniform 1-inch cubes. Trim the ends of the Brussels sprouts and cut each one in half. Aim for pieces that are roughly the same size so they cook evenly.

3. Combine ingredients in a large bowl: In a large mixing bowl, combine the cubed butternut squash and halved Brussels sprouts. This ensures everything gets coated evenly before going into the oven.

4. Dress the vegetables: Drizzle the olive oil and maple syrup over the vegetables in the bowl. Sprinkle with salt and black pepper. Toss everything together thoroughly with your hands or a large spoon until all the squash and Brussels sprouts are well coated.

5. Spread on the baking sheet: Transfer the coated vegetables to the prepared baking sheet. Spread them out in a single layer, making sure not to overcrowd the pan. If your baking sheet is too small, use two to ensure proper roasting and caramelization. Overcrowding will steam the vegetables instead of roasting them.

6. Roast until tender and caramelized: Place the baking sheet in the preheated oven and roast for 25-30 minutes. Halfway through the cooking time (around 15 minutes), remove the baking sheet from the oven and give the vegetables a good stir or flip them with a spatula. Continue roasting until the squash is tender when pierced with a fork and the Brussels sprouts are tender-crisp with slightly browned, caramelized edges.

7. Serve immediately: Once cooked to perfection, remove from the oven and serve hot. The sweet and savory aromas will be irresistible!