Step 1: Season the chicken - Pat the chicken thighs dry with a paper towel, then season them evenly with salt, black pepper, and garlic powder. Take a moment to really coat each piece well. This step builds the foundation of flavor.
Step 2: Sear the chicken - Heat the olive oil in a pan over medium heat. Place the chicken thighs skin side down and let them sear until golden brown. You are not cooking them through here, just building that beautiful color and flavor on the outside.
Step 3: Transfer to slow cooker - Once the chicken is nicely browned, transfer it to the slow cooker. Arrange the pieces in a single layer as much as possible.
Step 4: Make the sauce - In a bowl, whisk together the Sprite, sweet chili sauce, soy sauce, brown sugar, and cornstarch. Make sure the cornstarch is fully dissolved so the sauce thickens properly later.
Step 5: Combine everything - Pour the sauce evenly over the chicken in the slow cooker. Make sure each piece gets a good coating.
Step 6: Slow cook - Cover and cook on low for 5 to 6 hours. During this time, the chicken becomes tender and the sauce develops its rich flavor.
Step 7: Thicken the glaze - For the last 30 minutes, remove the lid. This allows the sauce to reduce and thicken into that sticky glaze that clings to the chicken.
Step 8: Finish and serve - Before serving, spoon some of the sauce over the chicken. This final touch makes each bite extra flavorful and glossy.