Gingerbread Advent calendar

Ingredients

• 250g golden syrup
• 150g sugar
• 100g margarine
• 500g flour
• 50g cocoa
• 1 teaspoon baking powder
• 1 teaspoon nutmeg
• 1/2 teaspoon ground cloves
• 1/2 teaspoon ground cinnamon
• 1/2 teaspoon ground ginger
• 1/2 teaspoon salt
• 2 eggs
• 1 lemon's rind
• 500g icing sugar
• 2 egg whites
• few drops lemon juice
• assorted food colouring