Preheat the oven to 350°F (175°C).

In a mixing bowl, whisk together the eggs, milk, sugar, vanilla extract, and cinnamon.

Add the cubed brioche bread to the mixture and let it soak for about 10 minutes.

If using, stir in the raisins.

Pour the mixture into a greased baking dish.

Bake for 45 minutes or until set and golden brown.

Let it cool slightly before serving.

Serve warm with whipped cream if desired.