In medium bowl or large measuring cup (I use a 4 cup measuring cup) stir together ketchup, soy sauce, honey, brown sugar, and garlic powder until well combined. If using the microwave: Heat for one minute and stir. Repeat in thirty second intervals, stirring after each, until smooth and well blended. If using a sauce pot: Heat over medium heat, stirring often, until it becomes hot enough to blend together well, with no lumps.
Place enough sauce in the bottom of a 9x13 baking dish to be able to spread it around and cover the bottom.
Place 1 cup flour in a shallow bowl. Dip each chicken breast into flour on both sides and place in the baking dish top side down. Spoon remaining sauce over, making sure to coat the chicken.
Place in 350 degree oven, uncovered. After 30 minutes, remove from oven and carefully flip chicken pieces over. Spoon sauce from baking dish over them again and return to oven for another 15-30 minutes, or until chicken is fully cooked, basting once more while cooking.
Remove from oven and baste again. Allow to sit for five minutes and baste once more before serving. Excellent served with yellow rice or mashed potatoes so you can spoon some of that delicious sauce over them!