Preheat the oven to 350°F (175°C). Grease a 9×9-inch baking dish or a similar-sized casserole dish.

Arrange the croissant pieces in the prepared dish, making sure they’re spread out evenly.

Sprinkle the blueberries evenly over the croissant pieces.

In a medium mixing bowl, beat the softened cream cheese with powdered sugar and vanilla extract until smooth and creamy.

In a separate bowl, whisk together the eggs, milk, cinnamon, and salt until fully combined.

Pour the egg mixture evenly over the croissants and blueberries, ensuring all the croissant pieces are soaked.

Drizzle the melted butter over the top and sprinkle with granulated sugar (if desired, for a crisp, sweet finish).

Bake for 35–40 minutes, or until the top is golden and the custard is set. You may need to cover with foil for the last 10 minutes to prevent over-browning.

Let the Blueberry Croissant Puff cool slightly before serving.

Optionally, dust with a little extra powdered sugar or drizzle with syrup before serving.