Prepare pasta following the directions on the package.
Melt the butter over medium heat in a large skillet or dutch oven.
Add garlic and continue to stir and cook until fragrant, about 30 seconds.
Add spinach; season with salt, pepper, and basil, and cook until spinach is wilted, about 1 to 2 minutes. Depending on the size of your skillet, you might have to cook the spinach down in batches.
Drain the cooked pasta and add it to the spinach mixture; add the cream cheese and milk.
Mix and stir until everything is well incorporated, and the cream cheese is melted.