Cook the macaroni according to the package instructions, then drain and set aside.
In a large saucepan, melt the vegan butter over medium heat.
Add the flour and whisk until smooth. Cook for 1-2 minutes.
Gradually add the non-dairy milk, whisking constantly to prevent lumps from forming.
Bring the mixture to a simmer and cook for 2-3 minutes, or until it thickens.
Add the nutritional yeast, Dijon mustard, garlic powder, onion powder, salt, and pepper. Whisk to combine.
Add the cooked macaroni to the saucepan and stir to coat with the cheese sauce.
Serve hot.
Note: You can also add vegetables like broccoli, peas, or carrots to this recipe to make it even more nutritious and delicious.