1. Separate the egg yolks and whites into two separate bowls.
2. Beat the yolks with all but 1 teaspoon of the sugar for about 3 minutes until light and fluffy. Combine half the flour with the baking powder and fold it into the egg yolks.
3. Heat the chocolate milk and butter in a small, heavy-bottomed saucepan over medium heat until the butter has melted.
4. Fold the chocolate milk and butter mixture, along with the salt, lemon zest and chocolate into the egg yolk/flour mixture.
5. Beat the egg whites with the remaining 1 teaspoon of sugar for approximately 3 minutes until stiff peaks form. Then carefully fold the egg whites into the rest of the batter.
6. Heat a frying pan over medium heat until it is nice and hot. Put some butter or oil into the pan to coat, and then pour about 50 ml of batter into the pan. Cook the pancake for about 2 minutes on each side. Repeat the process with the remainder of the batter.
7. Sprinkle the pancakes with icing sugar and serve immediately with blueberries and maple syrup.
The pancakes can also be made using a crêpe or blini pan.