Happy birthday chalkboard cake

Ingredients

• Equipment
• 30 centimetre x 40cm rectangular cake board
• Cake
• 2 x 450g packets double unfilled sponge slabs
• 1/2 x 453g tub chocolate frosting
• Decorations
• 3 x 125g packets ready-made black icing
• pure icing (confectioners’) sugar, for dusting
• 30 gram ready-made red icing
• 15 gram ready-made green icing
• 7 chocolate-coated licorice sticks
• non-toxic chalk