Preheat oven to 350°F and grease a 9x13-inch baking dish. Cook bacon in a large skillet until very crispy, then drain on paper towels and crumble into pieces.
Cook macaroni according to package directions until al dente, drain, and set aside.
In a large pot, melt butter with 2 tablespoons of reserved bacon fat over medium heat. Whisk in flour and cook for 2 minutes.
Slowly pour in milk and cream, whisking constantly until mixture thickens, about 6-7 minutes.
Remove from heat and stir in cheddar cheese, gouda, Dijon mustard, salt, and pepper until completely melted and smooth.
Fold in cooked macaroni and three-quarters of the crumbled bacon until evenly distributed.
Pour mixture into prepared baking dish and spread evenly.
Mix panko breadcrumbs with remaining bacon crumbles and sprinkle over the top.
Bake for 25-30 minutes until bubbly and golden brown on top. Garnish with fresh parsley before serving.