Preheat the oven to 400 degrees Fahrenheit (200 degrees Celsius).
Toss the cubed sweet potatoes with 1 tablespoon of olive oil and a pinch of salt and pepper on a large rimmed baking sheet.
Roast the sweet potatoes in the preheated oven for 15 minutes.
While potatoes roast, toss the chicken pieces with the remaining olive oil, smoked paprika, garlic powder, salt, and pepper in a mixing bowl.
Remove the baking sheet from the oven, move the potatoes to one side, and add the chicken pieces to the other side.
Return the sheet to the oven and roast for an additional 15 to 20 minutes until the chicken reaches an internal temperature of 165 degrees Fahrenheit and potatoes are tender.
Divide the cooked quinoa and baby spinach among four bowls.
Top each bowl with equal portions of roasted sweet potatoes and chicken, and garnish with avocado slices before serving.