Whisk eggs, milk, vanilla, cinnamon, sugar, and salt until smooth.
Dip each thick brioche slice into the mixture, coating both sides without letting it become overly soft.
Melt butter in a skillet over medium heat.
Cook the soaked brioche for about 3–4 minutes per side until deeply golden outside and tender inside.
Stack the warm slices on a serving plate.
Scatter raspberries and blueberries over the toast, then generously dust with powdered sugar.
Drizzle warm maple syrup over the French toast and serve immediately.
