Preheat your oven to 425°F (220°C) and position the rack in the center. Line a large rimmed sheet pan with parchment paper and ensure it is completely dry.
Peel the butternut squash, cut in half lengthwise, scoop out the seeds, and cut into uniform 1-inch cubes. Pat the cubes dry with paper towels to remove excess moisture.
Toss the squash cubes in a large bowl with 2 tablespoons of olive oil, salt, pepper, cumin, and smoked paprika until every piece is evenly coated.
Spread the seasoned squash in a single layer on the prepared sheet pan, ensuring the pieces are not touching to allow proper air circulation and caramelization.
Roast for 15 minutes without opening the oven door, allowing the squash to develop a golden sear on the bottom.
Remove the pan, flip each squash piece with a spatula, then scatter the feta cubes and pumpkin seeds across the pan and drizzle with the remaining 1 tablespoon of olive oil.
Return the pan to the oven and roast for another 12–15 minutes, until the squash is fork-tender with golden edges, the feta is softened and lightly browned, and the pumpkin seeds are toasted.
Whisk together the apple cider vinegar, maple syrup, and Dijon mustard, then slowly drizzle in the olive oil while whisking to emulsify. Season with salt and pepper to taste.
Arrange the mixed greens on a large platter, scatter over the red onion, dried cranberries, and pomegranate seeds, then let the roasted vegetables cool for 3–5 minutes before gently arranging them on top.
Drizzle about half the dressing over the salad and gently toss to combine, then serve immediately with extra dressing on the side.