For Frozen Fries: Cook the frozen French fries according to the package instructions until they are golden and crispy.
For Homemade Fries: Preheat the oven to 425°F. Wash and cut russet potatoes into ¼-inch thick sticks. Spread them evenly on a baking sheet lined with parchment paper, ensuring they are in a single layer to promote even cooking. Bake for 25-30 minutes, flipping halfway through, until they are golden brown and crispy.
Prepare the Cheese Sauce
Cook the flour. Melt the unsalted butter in a medium saucepan over medium heat. Once melted, whisk in the flour, stirring continuously to form a roux. Cook for 1 minute until the mixture is lightly golden and has a slightly nutty aroma.
Add milk. Gradually pour in the milk, continuing to whisk to ensure a smooth consistency. Bring the mixture to a gentle simmer, allowing it to thicken slightly.
Season it. Add the smoked paprika, garlic powder, ½ teaspoon of cayenne powder, Kosher salt, freshly ground black pepper, and ranch seasoning powder to the sauce. Stir well to incorporate all the spices.
Melt the cheese. Reduce the heat to low and slowly add the shredded cheddar cheese, one handful at a time, stirring continuously until the cheese is fully melted and the sauce is smooth.
Assemble the Voodoo Fries
Assemble. Place the cooked fries on a serving platter or individual plates. Evenly drizzle the warm cheese sauce over the fries, ensuring everything is generously coated.
Finish and serve. Sprinkle the remaining ½ teaspoon of cayenne powder over the top for an extra kick of flavor. Garnish with chopped fresh cilantro to add a touch of freshness and color. Serve and enjoy!