Cook the pasta as directed on the box to an al dente texture, strain, and let cool.
Melt the butter in a saucepan over medium heat; whisk flour into butter until smooth. Pour the milk into roux and whisk to combine. Cook and stir until mixture thickens, about 4-5 minutes. Add 3 cups of smoked gouda cheese and stir until cheese is melted, about 3 minutes more. Season with salt and pepper.
In a large mixing bowl, add the cooked pasta, cheese sauce, meatballs, and cherry tomatoes, and mix until combined. Transfer the mixture to a baking dish or cast iron pan. Top with remaining shredded gouda, and bake in a 375° pre-heated oven for 15-20 minutes, or until the meatballs reach an internal temperature of 145° and the cheese has become a desirable golden brown.
Remove from oven, and top with the sliced basil before serving.