Preheat oven to 350°F (175°C) and coat a 9x13 inch baking dish with non-stick cooking spray.
In a small mixing bowl, beat the softened cream cheese with 1 scoop of vanilla protein powder and 2 tablespoons of monk fruit sweetener until smooth.
Spread half of the cubed croissants in the bottom of the prepared baking dish.
Drop small dollops of the cream cheese mixture over the croissants and scatter half of the blueberries.
Layer the remaining croissant cubes on top.
In a separate large bowl, whisk together the whole eggs, egg whites, almond milk, remaining protein powder, remaining monk fruit sweetener, vanilla extract, and cinnamon.
Slowly pour the liquid custard over the croissants, ensuring all pieces are submerged or coated. Press down lightly with a spatula to aid absorption.
Top with the remaining blueberries.
Bake for 35 to 40 minutes, or or until the custard is set and the croissants are golden brown.
Allow the casserole to rest for 5 to 10 minutes before slicing and serving.