Preheat the oven to 375°F (190°C). Lightly grease a 9×13-inch casserole dish.
In a large skillet over medium-high heat, cook the ground beef until browned and cooked through, breaking it up with a spoon. Drain excess fat if necessary.
Add the diced onion, minced garlic, and diced jalapeños to the skillet with the beef. Cook for 5 minutes, stirring occasionally, until the onions are softened and the jalapeños are fragrant.
In a large mixing bowl, combine the softened cream cheese, sour cream, mayonnaise, shredded cheddar cheese, shredded Monterey Jack cheese, salt, black pepper, and smoked paprika. Mix until smooth and well combined.
Add the cooked beef mixture to the cheese mixture and stir until fully incorporated.
Transfer the mixture to the prepared casserole dish and spread evenly.
In a small bowl, combine the crushed buttery crackers with the melted butter. Sprinkle this mixture evenly over the top of the casserole.
Bake in the preheated oven for 25 to 30 minutes, or until the casserole is bubbly and the topping is golden brown.
Remove from the oven and let it cool for 5 minutes.
Garnish with chopped fresh chives before serving.