In a low shallow dish, such as a pie plate, or a 13- x 9-inch baking dish for larger batches, whisk the eggs until well beaten. Add the milk, sugar, and vanilla extract, and continue whisking until fully combined.

Heat 1 tablespoon of butter in a 12-inch to 14-inch skillet over MEDIUM heat. While the butter is melting, place a slice of brioche into the egg mixture, ensuring both sides are thoroughly coated. Once the butter has melted and started to foam, add the soaked brioche to the skillet. Repeat with additional slices, adding as many as will comfortably fit without overlapping. Cook each slice for 3 to 4 minutes per side, or until golden brown.

Transfer the cooked French toast to a platter to keep warm. If a warming tray is not available, place the French toast on a baking sheet and keep in a 200-degree oven until ready to serve. Wipe the skillet with a paper towel and repeat the process with the remaining butter, bread, and egg mixture.

Serve the French toast immediately, topped with warmed maple syrup and a side of fresh berries.