Add chopped bacon to your large pot over medium-high heat. Cook for 5 to 7 minutes, stirring occasionally, until the bacon is crispy and the fat has rendered into the pot.

Remove the cooked bacon with a slotted spoon, leaving the fat in the pot, and set it aside on paper towels.

Add the ground beef to the hot bacon fat in batches, breaking it apart with your spoon as it cooks. Brown for 8 to 10 minutes over medium-high heat, stirring occasionally, until most of the pink is gone.

Stir in the diced onion and cook for 3 to 4 minutes until it softens and becomes translucent. Add the minced garlic and cook for another 1 minute until fragrant.

Add chili powder, cumin, smoked paprika, brown sugar, black pepper, salt, and cayenne (if using) to the pot. Stir constantly for 2 to 3 minutes.

Stir in the tomato paste first, mixing it thoroughly into the spices for 1 minute. Add the crushed tomatoes and stir well to combine.

Pour in the drained kidney beans, pinto beans, and beef broth. Stir thoroughly to combine all ingredients, and return the cooked bacon to the pot.

Reduce heat to medium-low and bring the chili to a gentle simmer. Cook uncovered for 30 to 35 minutes, stirring occasionally, until the flavors meld and the chili thickens slightly.

Stir in the apple cider vinegar and Worcestershire sauce. Taste the chili and adjust salt, pepper, or spices as needed.

Let the finished chili rest for 10 minutes before serving.