Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper for easy cleanup.

Place the cubed sweet potatoes on the baking sheet and toss them with 1 tablespoon of olive oil, salt, and black pepper until evenly coated.

Roast the sweet potatoes in the preheated oven for 20 to 25 minutes, stirring halfway through, until they are tender and slightly caramelized on the edges.

While the potatoes roast, place the chopped pecans in a small dry skillet over medium heat and toast them for 2-3 minutes until fragrant, being careful not to burn them.

In a small bowl or jar, whisk together the remaining 2 tablespoons of olive oil, apple cider vinegar, maple syrup, and Dijon mustard until the dressing is emulsified and smooth.

Once the sweet potatoes are done, let them cool for about 5 to 10 minutes so they don't wilt the greens immediately.

In a large salad bowl, combine the spinach, roasted sweet potatoes, toasted pecans, dried cranberries, and chopped red onion.

Pour the maple mustard dressing over the salad and toss gently to combine just before serving to keep the greens crisp.