In a mixing bowl add the sugar and butter and mix until light and fluffy with a hand mixer. Add the egg and carry on mixing until it resembles cake batter.
Add ½ your Greek yoghurt and beat with a fork until everything is combined. Put to one side.
Dice the apple keeping the skin on. Break up ½ your mini apple pies into small pieces.
Place into the blender your broken mini apple pies along with ½ the Greek Yoghurt and the apple. Add to it 3 ice cubes and blend until smooth.
Finally add to it ¾ of your cake batter and blend one last time until smooth.
Pour your apple pie smoothie into smoothie glasses.
Place the rest of the batter into a piping bag and gently create a pretty icing top onto your smoothies.
Serve with apple flavoured caramel sauce and the spare mini apple pies.