Preheat oven to 350 degrees F.
Spray a muffin tin thoroughly with cooking spray.
Allow hash browns to thaw. Place in a dry towel to remove any extra moisture.
In a medium bowl, add hash browns, olive oil, rosemary, paprika, salt and pepper. Stir until well combined.
Evenly scoop hash brown mixture into the twelve muffin cups and press firmly down on the bottom and side to create a cup or basket-like mold.
Cook hash brown cups for 15-18 minutes and remove from oven.
In another medium bowl, crack eight eggs and whisk together.
Add spinach, tomatoes, cheese, and salt and pepper to taste. Stir until well combined.
Evenly distribute egg mixture into hash brown cups and cook for 20-22 minutes.
Allow to cool and use a knife to loosen hash brown cups from the pan.
Garnish with chives if desired.