Cut the sourdough bread into thick slices of 3/4 inch to 1 inch. Set aside.
In a shallow bowl, whisk eggs, milk, cream, cinnamon, sugar, and vanilla extract.
Dip each side of the sourdough bread slices for a few seconds into the egg mixture. Wait for a few seconds above the bowl to let the excess liquid run back to the bowl. Place the prepared bread slices onto a plate.
Warm some butter in a frying pan. When hot, fry bread slices for 2-3 minutes on one side, then flip on the other side. Add more butter if no more is left in the pan. Repeat these steps until all the French toast slices are cooked.
Serve immediately with a drizzle of maple syrup and fresh berries.