Heat the olive oil in a skillet over medium heat, then add the ground meat. Cook, breaking it apart and stirring until browned and cooked through, about 5-7 minutes. Transfer the cooked meat to the slow cooker.
Add chopped onion and minced garlic to the skillet; sauté until fragrant and the onion is translucent, about 3-4 minutes. Transfer the vegetables to the slow cooker with the meat.
Pour in the diced tomatoes (with juice), pumpkin puree, black beans, and add chili powder, cumin, smoked paprika, salt, and pepper to the slow cooker. Stir everything together until well combined.
Cover the slow cooker with its lid and set to low. Let it simmer gently for 4 hours, allowing the flavors to meld and the chili to thicken slightly.
After cooking, open the lid, and give the chili a good stir. Check the seasoning and adjust salt and pepper if needed.
Serve the pumpkin chili hot, topped with your favorite garnishes such as sour cream, chopped cilantro, or shredded cheese if desired. Enjoy the rich, velvety texture and bold aroma.