In a shallow, wide dish (such as a pie plate), whisk milk, eggs and vanilla. Dip both sides of the cinnamon swirl bread into the egg mixture. Coat both sides well.
In a large skillet set to medium heat, melt butter. Once melted and hot, add bread slices. Fry until golden brown, about 3-4 minutes. Flip and fry for 1-2 minutes on the other side.
Serve with maple syrup, powdered sugar for sprinkling, and/or fresh berries, if desired.