Start by cutting the Challah or Brioche Bread into thick slices. If possible, use stale or day-old bread for a sturdier texture that can soak up the custard mixture.
Make the custard mixture by whisking together half-and-half or cream, eggs, sugar, vanilla extract, and cinnamon until well combined. You can use an immersion blender or a regular blender to ensure the cinnamon is fully mixed into the custard.
Dip each slice of bread into the custard mixture, allowing both sides to soak for about 20 seconds. Carefully remove the bread, letting the excess custard drain off.
Cook low and slow on medium-low heat to ensure the center cooks through without the exterior browning too quickly. Add a generous amount of butter to create a perfect golden-brown crust.
Cook each side for 3-5 minutes, adjusting the heat if needed to prevent excessive browning.
Serve immediately with a sprinkle of powdered sugar, salted butter, and real maple syrup.