Preheat oven to 400 degrees F. Line a quarter sheet pan with parchment paper. Remove stems and use a spoon to carefully scrape away ribs of mushroom caps.

Place mushrooms top side down on the baking sheet. Bake in the preheated oven for 10 minutes. Remove and use a paper towel to soak up excess water.

While mushrooms are in the oven, heat olive oil in a medium frying pan. Once heated, add in fresh baby spinach and saute until cooked, about 5 minutes. Season with salt, black pepper and red pepper flakes.

Create a wall of the cooked spinach in the inside edges of the mushroom caps, leaving an opening in the center. Crack an egg into the center of each mushroom, and return sheet pan to the oven. Bake for 15 to 17 minutes, or until eggs are set.

Remove and serve with Dairy-Free Pesto, hot sauce or your favorite garnish.