Preheat oven to 350 degrees F. Grease/butter a 9x13-inch baking dish, set aside.
Prepare pasta according to package directions, set aside.
While pasta is cooking, melt 8 Tablespoons butter in a pan over medium heat.
When butter is melted, add the flour. Whisk until a uniform paste form then stir in salt and pepper.
While still over the heat, slowly pour in milk and heavy whipping cream, stirring continuously.
Continue to stir until the mixture thickens, Remove from heat.
Place prepared pasta into the prepared 9x13-inch baking dish.
Pour milk/flour mixture over top of the pasta.
Evenly sprinkle shredded Cheddar cheese, Pepper Jack cheese and bacon on top.
Stir together until everything is mixed and combined well.
In a small mixing bowl, melt the remaining 2 ounces of butter. Stir in breadcrumbs, this will resemble wet sand. Evenly distribute breadcrumbs overtop of pasta mixture.
Bake for 12-15 minutes or until the breadcrumbs begin to brown.
Broil for an additional 3 minutes making sure to watch carefully so topping doesn’t burn.
Top with chopped parsley if desired and serve.