Preheat your oven to 350 degrees F.
Rinse your boneless, skinless chicken breasts and pat dry with a paper towel; set aside.
Add the plain nonfat Greek yogurt, honey, sea salt, and dijon mustard (if desired) to a large bowl. Place the chicken into the bowl and toss to coat each in yogurt, cover with plastic wrap and place in fridge for 20 minutes.
After 20 minutes, place half of the crushed cornflake cereal in a ziploc bag and add half of the yogurt-coated chicken to the bag, shaking to coat.
Remove and place on a large greased baking sheet then repeat with the second half of the cereal and chicken.
Spray the chicken with cooking spray and bake for 20 to 25 minutes or until chicken is thoroughly cooked. Serve.