Crisp the bacon. In a large pot or Dutch oven over medium heat, cook the bacon until crisp. Transfer to a plate lined with paper towels.
Drain off most bacon fat, leaving about 1 tablespoon in the pot (or add butter if needed).
Sauté aromatics. Add butter (if using), onion, and garlic. Cook 2–3 minutes until softened and fragrant. Don’t let the garlic burn.
Add broth and seasonings. Pour in the chicken broth.
Stir in ranch seasoning, black pepper, and red pepper flakes if using. Bring to a gentle simmer.
Melt the cream cheese. Lower the heat. Whisk in the cream cheese cubes a few at a time until fully melted and smooth.
This step builds the creamy base, so take your time.
Stir in chicken and cream. Add the shredded chicken and heavy cream. Simmer on low 5–7 minutes to warm through and thicken slightly.
Add cheese and bacon. Stir in the cheddar a handful at a time until melted and glossy. Fold in most of the bacon, keeping some for topping.
Taste and adjust salt.
Finish with greens (optional). Add spinach and green onions. Simmer 1–2 minutes until wilted. For extra heat, stir in jalapeño now.
Serve. Ladle into bowls and top with reserved bacon, extra cheddar, and more green onions.
Serve hot.