Melt the butter in a large pot or Dutch oven over medium heat.
Add the diced onion, carrot, and celery. Season with the salt, black pepper, adobo seasoning, cumin, and chili powder. Cook for 8–10 minutes, stirring occasionally, until the vegetables have softened.
Add the minced garlic and cook for 1 minute.
Sprinkle the flour over the vegetables. Stir well and cook for approximately 3 minutes to remove the raw flour taste.
Slowly pour in the chicken broth while stirring continuously. Bring the mixture to a gentle simmer and cook until the broth begins to thicken.
In a separate bowl or measuring cup, whisk together the heavy cream and creamy jalapeño ranch seasoning mix. Pour it into the pot and stir until combined.
Stir in the buffalo sauce, cannellini beans, and drained Ro-Tel.
Reduce the heat to low. Add the softened cream cheese and stir until it has completely melted into the broth.
Add the freshly grated cheddar cheese. Continue stirring over low heat until the cheese is melted and the broth is smooth.
Add the shredded rotisserie chicken and stir well. Cook just until the chicken is heated through.
Taste and adjust the seasonings if needed. Serve with shredded cheddar, tortilla strips, fresh jalapeños, extra buffalo sauce, or your favorite toppings.