01 - Bring a large pot of salted water to a boil. Cook elbow macaroni according to package instructions until al dente. Drain thoroughly and set aside.
02 - In a saucepan set over medium heat, melt butter. Whisk in flour and cook for 1 minute, stirring constantly. Gradually pour in milk, whisking until mixture is smooth. Add shredded cheddar cheese and stir until fully melted and creamy.
03 - Add drained macaroni to the cheese sauce, folding gently to coat pasta evenly. Transfer mixture to an oven-safe baking dish.
04 - Stir melted butter into crushed crackers until evenly combined. Distribute cracker mixture across the top of the macaroni and cheese.
05 - Set oven to 375°F. Bake dish for 20 to 25 minutes, or until top is golden brown and edges are bubbling. Allow to cool briefly before serving.