Reduce the oven heat to 350F.
Boil the pasta noodles for 6-8 minutes until al dente. Set aside.
In a large saucepan over medium-high heat, melt the butter. One tablespoon at a time, add the flour, and vigorously whisk until smooth.
Add ¼ of the heavy cream and combine. Let the roux simmer and thicken for about 3 minutes.
Then add the remaining heavy cream, evaporated milk, and brie cheese and cook for about five more minutes until the brie cheese is fully melted.
Next, add all but ½ cup of the cheddar cheese, and stir. Cook for another 3-5 minutes until the cheddar is fully melted and combined. Then remove the cheese sauce from the heat. Add in the garlic powder, onion powder, salt, and pepper.
In a large bowl, add the cooked pasta noodles and cheese sauce. Gently stir to combine.
Transfer the mac and cheese into a large casserole dish and top with the remaining cheddar cheese and brioche breadcrumbs. Bake for 30 minutes uncovered until bubbly and golden brown.