Preheat oven to 450 degrees F. Lightly coat a baking sheet with nonstick cooking spray. Place chicken breasts on the baking sheet.
In a small bowl, combine hummus, minced garlic, paprika, cumin and chili powder. Using a spoon, scoop hummus on top of chicken, spreading evenly to coat. Squeeze one lemon half over each chicken breast.
Bake for 25 to 30 minutes, or until chicken is cooked through and hummus has crisped.