Start by boiling a large pot of water. Add the elbow macaroni and cook according to package instructions until al dente, usually about 8 to 10 minutes.

Once cooked, drain the macaroni in a colander and set aside.

In a medium saucepan, melt the unsalted butter over medium heat.

Whisk in the flour until smooth and cook for about 2 minutes to make a roux.

Slowly pour in the low-sodium vegetable broth and milk while whisking continuously. Bring the mixture to a gentle simmer.

Once the sauce has thickened slightly, reduce the heat to low and add the shredded cheddar and mozzarella cheeses. Stir until melted and creamy.

Add garlic powder, onion powder, and black pepper to the cheese sauce, stirring to combine.

Add the drained macaroni to the cheese sauce and stir well to coat.

Serve the mac and cheese immediately or transfer it to a baking dish to bake. If baking, preheat the oven to 350°F and bake for 15 to 20 minutes until bubbly.