Allow slices of brioche bread to sit out, uncovered, overnight to help dry out the bread. If the bread is still soft and fresh, arrange the slices of brioche bread on a lined baking sheet. Bake the slices in a 300 F (149 C) oven for about 15 minutes.
12 slices stale or day old brioche bread
In a large mixing bowl whisk in the eggs, milk, sugar, flour, vanilla extract and ground cinnamon until smooth and well combined.
4 large eggs, room temperature, 1 cup (240 ml) whole milk, ¼ cup (50 g) sugar, ¼ cup (30 g) all purpose flour, 2 teaspoons (10 ml) vanilla extract , 1 teaspoon ground cinnamon
Heat the pan over medium-low heat until the butter fully melts and begins to sizzle. Swirl the butter around the pan to fully coat the bottom of the pan. Dip each side of sliced brioche bread in the vanilla custard for 30 seconds right before frying on the skillet or griddle.
1 - 4 tablespoons (12 - 57 g) unsalted butter for cooking, as needed
Place 2 - 4 slices of custard coated brioche bread onto the hot pan. Fry one side of the bread for 3 - 4 minutes or until the toast is golden brown. Flip the toasted brioche bread and repeat frying on the other side for 3 - 4 minutes or until golden brown. Transfer the french toast brioche slices to a serving plate or lined baking sheet.
When its time to serve the brioche french toast, top the slices with a light dusting of powdered sugar and fresh mixed berries. If you would like, heat up maple syrup to serve alongside the french toasted brioche bread.