Combine Ingredients: Place the boneless, skinless chicken breasts into the bottom of your 5- to 6-quart slow cooker. In a separate small bowl, mix the chili powder, ground cumin, garlic powder, onion powder, and smoked paprika. Sprinkle this seasoning mixture evenly over the chicken. Pour the entire jar of low-sugar salsa over the seasoned chicken.

Cook: Secure the lid on the slow cooker. Cook on the LOW heat setting for 6 to 7 hours, or alternatively, cook on the HIGH heat setting for 3.5 to 4.5 hours. Cooking times can vary depending on the slow cooker and the thickness of the chicken.

Check Doneness: Once the minimum cooking time is reached, test the chicken for tenderness. It should shred easily when pulled with two forks. If the chicken is still firm, replace the lid and continue cooking for an additional 30-60 minutes on LOW or 20-30 minutes on HIGH, testing again afterwards.

Shred Chicken: When the chicken is fully tender, use two forks to shred it directly within the slow cooker. Break the chicken down into bite-sized strands, mixing it thoroughly with the salsa and the accumulated cooking liquids in the pot.

Serve or Store: The pulled fiesta chicken is ready to be served warm. It's excellent in tacos, burrito bowls, salads, or as a main protein. To store, let the chicken cool completely, then transfer it to an airtight container and refrigerate for up to 4 days.