Whisk together milk, eggs, vanilla bean seeds and salt. Pour the batter into a baking dish.
Place the sourdough bread slices into the batter and let sit for about one minute on each side. Heat the pan with some butter in it. Fry the bread slices until golden brown, for about five minutes. Flip it over and fry on the other side for five minutes as well.
Whisk together the espresso with the mascarpone cheese and the honey. Place in the refrigerator until the french toast is ready to serve.
Place the bread slices one on each plate. Divide the espresso mascarpone evenly on each bread slice. Sprinkle with confectioners sugar as decoration and add some chopped pistachios. Enjoy!