Preheat your oven or air fryer to 400°F (200°C).

Arrange the frozen French fries in a single layer on a baking tray or in the air fryer basket.

Bake or air fry for approximately 20 minutes until golden-brown and crispy.

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

Whisk in the all-purpose flour and cook for about 2 minutes to create a roux.

Slowly add the milk while whisking constantly, stirring until thick and creamy.

Stir in salt, ground black pepper, ranch seasoning powder, and cayenne powder.

Add shredded white cheddar cheese and stir until melted and smooth.

Transfer baked fries to a serving platter and drizzle with cheese sauce.

Serve immediately and enjoy!