Slice the bread into 1-inch thick pieces and arrange them in a shallow dish.
In a mixing bowl, whisk together the eggs, milk, cocoa powder, sugar, and salt until smooth and the cocoa is fully integrated, with a slightly frothy top.
4 slices bread (preferably brioche or thick-cut)
Pour the chocolate egg mixture evenly over the bread slices, ensuring each piece soaks for about 2 minutes. Flip the slices to coat both sides thoroughly.
4 slices bread (preferably brioche or thick-cut)
Preheat a non-stick skillet or griddle over medium heat and add a tablespoon of butter. Once melted and sizzling, carefully transfer the soaked bread slices onto the hot surface.
4 slices bread (preferably brioche or thick-cut)
Cook the slices for about 3-4 minutes per side, or until golden brown and slightly crispy on the edges. Use a spatula to flip when the underside shows deep golden color and a slight aroma of caramelized cocoa.
4 slices bread (preferably brioche or thick-cut)
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.