Whisk together brown sugar, vegetable oil, eggs and pumpkin puree until well combined. Make a well in the centre of the dry ingredients and pour in pumpkin mixture. Stir to mix. Spoon mixture into cupcake cases. Bake for 15-20 minutes until cooked and golden. Transfer to a baking rack to cool. Once cupcakes are cold, pipe cream cheese frosting onto the top of the cupcakes. Place 3 choc bits on the frosting to make the eyes and mouth.