1. For the maple cranberry sauce: Combine all the ingredients in a small saucepan. Bring to a boil over high heat, then reduce the heat to maintain a simmer.
2. Simmer, uncovered, for 8-10 minutes, stirring occasionally, until most of the berries have popped and the sauce has thickened.
3. Transfer to a serving bowl and refrigerate for at least 1 hour before serving. Store in the refrigerator for up to 3 months.
4. For the bacon apple chicken burgers: Peel and mince onion. Peel, core, and mince apple. Mince rosemary.
5. Place the bacon in a cold skillet, then turn on the heat to medium-high. Cook, flipping once or twice, until the bacon is crispy.
6. When the bacon is crispy, remove it from the pan and add the onion to the bacon fat in the pan.
7. Sauté for 5 minutes over medium-high heat, stirring occasionally, until the onion is starting to soften.
8. Add the apple and rosemary and continue sautéing until the onion is browned and both the onion and apple are soft, 5-8 minutes.
9. Remove from the pan with a slotted spoon and allow to cool slightly. Do not clean the pan; you will use it to cook the burgers.
10. When the bacon is cool enough to handle, chop into small pieces (think bacon bit size).
11. Combine the ground chicken, bacon, apple and onion mix, salt, and pepper in a bowl. Mix well with your hands and form into 6-8 ounce patties.
12. Preheat the pan over medium heat. If there is no bacon fat left in the pan, add more bacon fat.
13. Fry the patties in the pan, in batches if needed to prevent overcrowding, until fully cooked, 15-25 minutes total flipping once.
14. To ensure that the burgers are fully cooked, check the internal temperature with a meat thermometer: it should read 160F.
15. Serve with chilled maple-cranberry sauce.