Preheat the oven to 350°F (175°C).

Grease a 9x13 inch baking dish.

Cut the cinnamon roll dough into quarters.

In a large bowl, whisk together the eggs, milk, vanilla, cinnamon, and lemon juice.

Gently fold the cut cinnamon rolls and blueberries into the egg mixture.

Pour the mixture into the greased baking dish.

Bake for 30-35 minutes until the top is golden and the center is set.

While the casserole bakes, prepare the icing by whisking the powdered sugar with a little milk if necessary.

Once the casserole is baked, remove it from the oven and let it cool for a few minutes before drizzling with icing.