In a large saucepan or skillet, melt the butter over medium heat. Once melted, add the flour and whisk continuously until the mixture becomes smooth and bubbly, about 2 minutes.

Gradually pour in the milk while whisking constantly to prevent lumps from forming. Continue whisking until the sauce thickens and comes to a boil, approximately 5-7 minutes.

Reduce the heat to low and add the onion powder, white pepper, and cayenne pepper (if desired). Stir well to incorporate the spices into the sauce.

Optional: For those who prefer a spicier mac and cheese, this is the perfect time to add hot sauce to taste. Adjust the quantity based on your desired level of spiciness.

After the sauce has reached a smooth consistency, pour in the heavy cream and stir until well combined. The addition of heavy cream enhances the richness and creaminess of the sauce, taking it to another level of indulgence.

Gradually add the shredded white cheddar cheese to the sauce, stirring continuously until the cheese melts and the sauce becomes smooth and velvety.

In a large mixing bowl, mix the cooked elbow macaroni with the cheese sauce until all the macaroni is well coated. Ensure that each macaroni is thoroughly covered in the luscious cheese sauce to achieve the desired flavor and texture.

Preheat the oven to 350°F (175°C). Transfer the mac and cheese mixture to a baking dish and spread it out evenly. For an extra cheesy touch, sprinkle additional cheese offerings on top of the mac and cheese.

Place the baking dish in the preheated oven and bake for approximately 20-25 minutes or until the top is golden and bubbling.

Once baked, remove from the oven and let it cool for a few minutes. Serve while still warm and enjoy the richness and cheesy goodness of Arby's mac and cheese.