Preheat oven to 400 degrees. Place squash cut-side down on parchment-lined baking sheets. Bake until easily pierced with a fork and the flesh can be easily pulled away from the skin, about 35 minutes. Remove squash from the oven once cooked through. Turn over so the cut side is now facing up. Once cool enough to handle, remove flesh with a spoon to a bowl, being sure not to rip the skin.

In a large pan, cook the bacon on medium heat until crispy on both sides and the fat is rendered. Chop bacon and set aside. Strain bacon grease into a container for later use, leaving 1 tsp to coat the pan.

Add celery and apple to pan, stirring until the apple begins to brown, about 2-3 minutes.

Add ground beef to pan and break up with a wooden spoon into small pieces as it browns. Once the beef is almost cooked through, add the chopped sage and rosemary, coconut flour, cinnamon, oregano, coconut aminos, vinegar, lemon zest, and sea salt, and mix well. Now stir in the squash flesh until it is evenly distributed with the beef mixture.

Lower oven temperature to 350 degrees. Spoon mixture back into squash halves, top with chopped bacon and bake for an additional 10 minutes. Serve warm.