Preheat the oven to 400°F and line a baking sheet with parchment paper. Cut the squash in half crosswise and scoop out the seeds. Set the squash cut-side down and bake until soft, about 40 minutes.
Meanwhile, cook the bacon in a large skillet over medium heat until crisp. Remove to a paper towel-lined plate. In the same skillet, cook the ground beef, breaking up any clumps with the back of a wooden spoon.
When the beef is almost cooked through, about 7 minutes, add the garlic, salt, and pepper. Cook until no longer pink, another 2 or 3 minutes.
Stir in the ketchup and Worcestershire sauce. Scoop the flesh out of the squash and stir in until well mixed into the ground beef. Spread out evenly over the bottom of the skillet.
Sprinkle with shredded cheddar cheese and cover the skillet. Reduce heat to low and let the cheese melt, about 5 minutes. Sprinkle bacon over top and serve.
Notes
Feel free to adjust ingredients for taste. This casserole is keto-friendly and customizable!