Carefully wash the peaches and cut each peach in half, starting along the crease of the peach and running your small paring knife all the way around. Twist the two halves to release one side from the pit and then use the tip of a knife or fork to pry the pit out from the remaining side.
Scoop out some flesh and place it into a bowl.
In the same bowl, add the crumbled amaretti cookies.
Mix until well combined and then add the coarsely grated chocolate.
Dilute the liqueur with some water and pour it over the peaches: let them marinate for 10 minutes.
Drain the peach halves from the marinade; lay them cut side up in a baking tray lined with parchment paper. Spoon the filling into the peach cavities.
Sprinkle the peaches with brown sugar.
Pre-heat a static oven to 350°F (180°C). Cover the peaches with aluminum foil and bake for about 40 minutes. Remove the foil and bake for 5-10 minutes more until golden and crispy.