Preheat the oven to 350°F (175°C) and grease a 9x13-inch baking dish.

In a large bowl, whisk together the eggs, milk, granulated sugar, vanilla extract, cinnamon, and salt until well combined.

In a separate bowl, beat the softened cream cheese until smooth and creamy.

Add half of the egg mixture to the cream cheese and mix until fully combined.

In the greased baking dish, layer half of the torn croissant pieces, followed by half of the blueberries.

Pour half of the cream cheese mixture over the croissants and blueberries, then repeat the layering with the remaining croissants, blueberries, and cream cheese mixture.

Pour the remaining egg mixture evenly over the top of the casserole, ensuring all croissant pieces are soaked.

Let the casserole sit for about 15 minutes to absorb the liquid.

Bake in the preheated oven for 35-40 minutes, or until the top is golden brown and the casserole is set.

Remove from the oven and let it cool for a few minutes before serving. Dust with powdered sugar if desired.