Preheat oven to 425 degrees. Line a baking sheet with aluminum foil, set aside. Peel and dice sweet potatoes and place in large bowl. Add 3 tablespoons of olive oil and add in paprika, cumin, chili powder, coriander, cayenne and salt and pepper. Toss to coat evenly, then pour onto prepared baking sheet.
Bake for 20-25 minutes, or until tender and slightly caramelized, stirring once halfway through baking.
While the potatoes are roasting, in a large skillet, heat remaining 1 Tbsp olive oil over medium-high heat. Add onion and saute about 5 - 6 minutes, adding in garlic during last minute of cooking. Reduce heat a bit, to medium-low, add in drained and rinsed black beans, and corn, and heat until warmed through.
Add in roasted sweet potatoes, drizzle with honey and lime juice and cilantro. Stir to combine well. Serve over warm tortillas with desired toppings.
Combine sour cream, cilantro, lime juice, honey, salt, pepper, and chili powder in a food processor and pulse until smooth. Serve drizzled over the tacos.