Transfer the chicken breasts to a large gallon-size bag or a baking dish.

Prepare the marinade by adding soy sauce, ketchup, pulverized pineapple, pineapple juice, honey, vinegar, and sriracha to a bowl and whisk until combined. Pour half of the marinade over the chicken and refrigerate for 30 minutes to 2 hours.

Preheat the grill to 450°F. Remove chicken from the fridge and let it rest for 10-15 minutes. Clean the grill grate.

Season the pineapple slices with chili powder and salt.

Transfer the marinated chicken to the grill over direct heat and cook for 8 minutes per side.

Grill the pineapple slices for 2-3 minutes per side until grill marks appear. Remove from the grill.

Pour remaining marinade into a saucepan and bring to a boil. Reduce to simmer for 2-3 minutes. Remove from heat.

Cook the chicken until internal temperature reaches 165°F.

Serve the pineapple slices over the grilled chicken and pour the sauce over. Serve immediately.