Bring 500 ml of milk to a boil with a cinnamon stick, lemon peel, and 150 g of sugar.
Let the milk cool until it’s lukewarm.
Meanwhile, use a knife to remove the crust from the bread, leaving only the soft inside.
Once the milk is lukewarm, temper the 3 egg yolks (set aside the egg whites and the 3 whole eggs for later—you can use the egg whites to make farófias or molotof). Add a little of the warm milk to the yolks, whisking vigorously until well combined.
Fill a pot halfway with vegetable oil. The oil should reach 180°C (350°F).
Place the bread in the milk and egg yolk mixture. Soak it well, turning the pieces so they are completely saturated.
Shape the bread by gently pressing it together, but don’t squeeze out too much of the liquid. You want the rabanadas to stay nice and moist.
Beat the 3 whole eggs with a fork and dip each piece of bread into the beaten eggs.
Once the oil reaches 180°C (350°F), fry the rabanadas, turning them once they are golden brown.
Once golden brown on both sides, remove them from the oil and place them on paper towels to drain off the excess oil.
Sprinkle the rabanadas with sugar and cinnamon.