In a mixing bowl, whisk together eggs, milk, cocoa powder, sugar, and salt until smooth.
Heat a skillet or griddle over medium heat, adding a tablespoon of butter. Allow the butter to melt completely before adding the bread slices.
Dip each slice of bread into the batter for 2-3 seconds, ensuring both sides are well-coated but not overly soaked.
Place the coated bread slices onto the skillet and cook for 2-3 minutes per side until golden brown and crispy.
Remove the cooked French toast from the skillet and place on a plate. Optionally, dust with powdered sugar or drizzle with melted chocolate before serving.