Prepare spaghetti according to directions on box. Drain and keep warm by putting lid back on pot.

In a large bowl, mix together shrimp, half of cajun seasoning, salt and pepper.

Heat a large dutch oven over medium-high heat. Add oil. Once hot, add in shrimp and cook for 3-4 minutes total, stirring occasionally.

Remove shrimp from heat and place back in bowl.

Add butter to hot pan where shrimp was, then add minced garlic. Mix and let cook 30 seconds over medium-high heat, then add in diced tomatoes and milk.

Take ¼ cup of the milk mixture out of the pot and place in bowl, whisk in flour. This will create a roux, a thick sauce that will help to thicken our main dish. Once all mixed together, add the roux back into the main pot and whisk until all combined.

Stir in parmesan cheese and remainder of cajun seasoning. Let simmer over medium heat for 5-6 minutes, or until has thickened. Be sure to stir occasionally. Once thick, turn off heat.

Add shrimp back into sauce, in addition to spaghetti. Mix together using tongs until all combined. Then add in bag of baby spinach and mix. It will take a few minutes to wilt down, so you can put the lid back on to let it steam, or just keep mixing until spinach has wilted.

Top with chopped parsley and extra parmesan and serve!