Beat eggs, milk and vanilla together.
Slice the challah up. Making french toast is excellent way to use up stale bread or in this case a couple of days old challah. Sure, fresh challah will be just as good but mind that it will soak up the egg/milk mixture much quicker than the stale challah. Check out how to make: Challah Recipe
Soak the slices into the egg and milk mixture. Try one at the time and once we get the feel of how much liquid can be absorbed by the challah, go wilder.
Heat butter in a skillet then place the soaked challah in.
Once one side got golden brown, flip it over.
When both sides of the challah french toast get the desired golden brown color, remove from the skillet and let them cool somewhat. Serve as it is or sprinkle with cinnamon and drizzle it with honey.
Enjoy!