Begin by bringing a large pot of salted water to a rolling boil. Add the elbow macaroni and cook according to package instructions until al dente, about 7–8 minutes. Once cooked, drain the pasta well in a colander and set it aside.

In a medium saucepan over medium heat, melt 2 tablespoons of unsalted butter. Once foamy, whisk in 2 tablespoons of flour and cook for about 1 minute until it’s slightly golden, creating a roux.

Gradually pour in 1 cup of whole milk while whisking vigorously to prevent lumps. Cook the mixture over medium heat for 2–3 minutes, stirring occasionally, until it thickens to a smooth, velvety consistency.

Lower the heat and stir in 1½ cups of shredded sharp cheddar cheese and ¼ cup of shredded mozzarella cheese. Add ½ teaspoon of mustard powder, ¼ teaspoon of garlic powder, and season with ¼ teaspoon of salt and black pepper to taste.

Fold the cooked macaroni into the cheese sauce, ensuring each piece is generously coated and nestled in the creamy goodness.

Take a flour tortilla and spread a generous portion of the mac and cheese mixture over half of the tortilla, leaving one edge clear. Top it with another tortilla, pressing gently to secure the filling.

Heat a skillet over medium heat and add a small pat of unsalted butter. Once melted, place the assembled quesadillas in the skillet, cooking for about 2–3 minutes on each side or until they turn a golden brown and crisp.

After cooking, let the quesadillas rest for 1–2 minutes on a cutting board. This will help firm up the filling, making them easier to slice.