Place a large heavy pot or Dutch oven over medium heat. Add the chopped bacon and cook, stirring occasionally, until crisp, 7–9 minutes. Use a slotted spoon to transfer the bacon to a paper towel–lined plate, leaving about 2 tbsp of bacon fat in the pot.

Add the butter to the pot with the bacon fat. Once melted, add the diced onion and celery. Sauté over medium heat until softened and translucent, 4–5 minutes.

Stir in the minced garlic and cook until fragrant, about 30 seconds, being careful not to brown it.

Pour in the chicken broth and scrape up any browned bits from the bottom of the pot. Stir in the shredded chicken and cauliflower florets, if using. Bring the mixture to a gentle simmer.

Reduce the heat to low. Add the heavy cream and ranch seasoning mix, smoked paprika, dried dill (if using), black pepper, and salt. Stir well to combine and keep at a very gentle simmer.

Add the softened, cubed cream cheese to the pot. Whisk or stir constantly over low heat until the cream cheese is fully melted and the broth looks smooth and creamy, 3–5 minutes. Do not let the soup boil.

Turn off the heat. Gradually add 1 1/2 cups of the shredded cheddar cheese, a small handful at a time, stirring constantly until each addition is fully melted and the soup is thick and silky.

Taste the soup and adjust seasoning with additional salt, pepper, or ranch seasoning as needed. If the soup is thicker than you like, thin it with a bit more chicken broth; if it is too thin, let it simmer gently on low for a few more minutes to reduce slightly.

Ladle the soup into bowls. Top each serving with the reserved crispy bacon, the remaining 1/2 cup shredded cheddar, sliced green onions or chives, and jalapeño slices if desired. Serve hot.