Preheat the oven to 390 degrees F. Coat a sheet pan with cooking spray and arrange the mushrooms on the pan. Set aside.

Heat 2 tablespoons oil in a frying pan over medium heat. Add the spinach and cook uncovered until the spinach is completely wilted. Squeeze out all of the excess liquid from the spinach in a colander with the back of a spoon.

Place the cream cheese, mozzarella cheese, oregano, breadcrumbs, spinach, cilantro and hot sauce in a bowl. Stir to combine. Add salt and pepper to taste.

Using a teaspoon, fill each mushroom cap with the spinach mixture, rounding tops off.

Bake in oven until tops are golden and mushrooms are cooked through, about 20-25 minutes. Serve immediately.