Cut the crusts off the bread, then cut each slice into 9 equal cubes.
In a medium bowl, whisk together eggs, milk, and salt.
In a shallow bowl, mix sugar and cinnamon until combined.
Melt 1 1/2 tablespoons butter in a non-stick pan over medium-high heat without browning.
Quickly toss half the bread cubes in the egg mixture, shaking off excess. Add to the pan and sauté, turning gently, until golden on all sides, about 2–3 minutes.
Transfer immediately to the cinnamon sugar mixture and toss to coat.
Repeat with remaining butter and bread cubes.
Serve Cinnamon French Toast Bites immediately with maple syrup for dipping.