Whisk the egg, milk, and cinnamon together in a wide, shallow bowl.

In a large skillet over medium heat, melt the first tablespoon of butter.

Dip 3 slices, one at a time, into the egg-milk mixture, and place the slices in the frying pan, as soon as the butter stops bubbling and before it turns brown. Cook the slices on both sides until golden brown. Repeat with remaining tsoureki slices, replenishing the frying pan with a little butter when needed.

Serve the tsoureki French toast hot, drizzled with Greek honey or sprinkled with confectioner’s sugar and a little cinnamon.