Cook pasta according to package directions. Drain and place into a large bowl. In a large saucepan over medium heat, melt butter. Add in minced garlic and cook for a few minutes until fragrant.
Add in the flour and cook for a minute to brown. Add in milk, grated parmesan cheese, salt, and pepper. Continue to cook over medium heat, while whisking constantly until it is thickened and smooth. Mix the sauce with the cooked pasta.