Place all cake ingredients in a mixing bowl and mix until just smooth.
Pour into greased and lined 30 x 22cm tin.
Bake in preheated oven 180°C, 160°C fan, Gas mark 4 for 30-35 minutes. Cool on wire tray.
For the icing, place all ingredients in a bowl over a pan of hot water and stir until smooth and glossy. Remove from heat and leave until cold. Beat until thick enough to spread over traybake.
Cut into 21-24 bars. Place 50g icing sugar in a bowl and add a few drops of water to make a thick icing. Use to attach the oreos and sweets to create your monsters. Place remaining icing in a small piping bag with a plain nozzle and pipe the ‘mouths’ on your monsters.
Hint: a little of the icing can be coloured red if you want to use the oreo biscuits to make eyeballs. Use a M&M for the centre of the eye and red icing for the veins.
- Temperature: 180C oven, 160C fan, Gas 4 oC
- Baking time:
- Serves: 20-24