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

Place a frying pan or griddle over medium heat and add a tablespoon of butter.

Dip each slice of brioche into the custard mixture, ensuring both sides are well-coated.

Carefully place the soaked brioche in the heated pan and cook for about 3-4 minutes on each side until golden brown.

If cooking in batches, keep the cooked French toast warm in a low oven.

Serve the French toast warm on plates, drizzled with maple syrup and sprinkled with powdered sugar if desired.

Top with fresh berries, whipped cream, or yogurt if desired.