Preheat your oven to 350oF (180oC). Line a standard cupcake tin with paper liners.
In a bowl, mix together the flour, baking powder, salt and cinnamon.
Using your KitchenAid® Artisan Mini, cream together the butter and sugar until fluffy and pale in color, about 4 minutes.
On medium high speed, beat in the egg until combined.
Lower the speed on the mixer and mix in the flour and milk until just combined.
Next add in the grated apple and mix in until just combined. Take care not to overmix your batter as it can toughen your cupcakes.
Spoon the cupcake batter into your lined cupcake tin. It will make roughly 12 cupcakes.
Bake for roughly 20-25 minutes or until firm to the touch. Set aside to cool completely.
Using a whisk attachment, beat softened butter on medium speed. Beat for 3 minutes until smooth and creamy.
Add sifted powdered sugar, one spoonful at a time until all the sugar has been incorporated.
Now add in your food coloring (if desired) and milk. Increase to high speed and beat for 3 minutes until your frosting is light and fluffy.
Color the buttercream with a few drops of green and red food coloring (I use my all-natural food dye recipe but you can use store bought as well).
Fill a piping bag fitted with a star nozzle full of buttercream frosting. Decorate the tops of the cupcakes to look like Apples.
Store the cupcakes in an airtight container at room temperature for up to 4 days.