Bring a large pot of water to a boil and cook the 16 ounces uncooked elbow macaroni according to the package directions until al dente. Drain and set aside.
Preheat the oven to 400 degrees Fahrenheit and spray a 9x16-inch baking dish with non-stick cooking spray.
In the same large pot used for the pasta, heat the ¼ cup unsalted butter over medium-high heat. Add the 4 de-seeded and diced jalapeñoss and cook for 3 minutes, stirring frequently.
Whisk the ¼ cup all-purpose flour into the butter and jalapeños, it should create a thick paste. Slowly whisk in the 3 cups whole milk and 2 cups heavy whipping cream until smooth and incorporated. Bring to a gentle boil, reduce the heat to low, and simmer.
Add the 4 ounces softened cubed cream cheese and 2 cups white cheddar cheese and stir, simmering until melted and incorporated. Stir in the 1 cup cooked and diced bacon, 1 teaspoon salt, 1 teaspoon pepper, 1 teaspoon garlic powder, and ½ teaspoon onion powder.
Add the cooked pasta back to the pot and stir to coat well in the sauce. Pour the macaroni and cheese mixture into the prepared baking dish.
In a medium bowl, mix the 1 cup panko breadcrumbs and 1 tablespoon melted butter until the crumbs are evenly coated in the butter.
Spread the 1 cup shredded white cheddar cheese over the macaroni in the baking dish, followed by the panko mixture, and then finally the 1 de-seeded and sliced jalapeño and ½ cup cooked diced bacon.
Bake the dish for 10-15 minutes until the top is melted and golden brown. Remove from the oven and let cool for a few minutes before serving.