Preheat oven to 180°C.
Separate the egg yolks from the egg whites. Beat the eggs with the sugar and vanilla sugar until the mixture whitens (beat well!). If you want to add lemon juice, now's the time!
Gradually add the flour, cornstarch and baking powder.
Beat egg whites until stiff. Gently fold into the remaining dough.
Butter (with vegetable margarine for a lactose-free version) and flour the mould, paying particular attention to the nooks and crannies (to avoid losing a lamb's ear when unmoulding!). Fill the mould 3/4 full with the dough (no more, it will puff up).
Bake at 180°C for approx. 40-45 minutes. Once out of the oven, wait until the tin is lukewarm, then carefully remove from the mould. Sprinkle with powdered sugar and tie a ribbon around the lamb's neck. Taste fairly quickly (ideally the same day), as lamala dries out quickly!