Preheat the oven to 425°F. Toss the sweet potato cubes with 1 tablespoon olive oil, cumin, salt, and pepper on a baking sheet. Spread them in a single layer and roast for 25 minutes until tender and lightly browned at the edges.
While the sweet potatoes roast, heat a small dry skillet over medium heat. Add the pepitas and toast for 3 to 4 minutes, shaking the pan often, until they turn golden and start to pop. Set aside to cool.
In a large bowl, whisk together the remaining tablespoon of olive oil, minced chipotle pepper, and lime juice to form the dressing.
Add the roasted sweet potatoes, pinto beans, diced red onion, and chopped cilantro to the bowl with the dressing. Gently toss everything until evenly coated.
Sprinkle the toasted pepitas over the top just before serving.