Make up the cake mix as instructed by adding water and oil (I used melted butter but the result will be the same).
Peel and chop the apples into small pieces, and mix into the cake batter.
Add a little red and yellow gel food colouring to give the cake mixture a light orange colour.
Grease a 12-hole muffin tin and place approx 2 dessert spoons of the mixture into each hole, using up all of the mixture.
Bake at 180 degrees for around 25 minutes.
Remove from the oven and allow to cool completely. Gently ease from the tin.
Make the green butter cream by creaming the butter with an electric whisk then adding the icing sugar in two batches, and mixing in between until soft. Add a little green gel food colouring to reach a light green colour.
Split each cake, pipe the buttercream in the middle and pipe a little swirl on top for the pumpkin's stalk.