Preheat the oven to 180˚C.
Lightly grease the inside of the tin.
Put margarine and sugar into the medium bowl and cream together with a wooden spoon.
Weigh out your flour, add the mixed spice and put to one side. Beat the 4 free range eggs in a separate bowl and slowly add to your creamed mixture, if it starts to split don’t worry, gradually add a little of your flour and mix in, then the rest of the eggs and then the rest of the flour and vanilla essence. Mix until everything is combined. Add the pieces of apple and fold them in.
Spread evenly in the tin, sprinkle the top with demerara sugar evenly over the top. Place in the centre of the oven. Cook for approximately 40 mins, it should be firm on the top if it isn’t ready turn the oven down to 160c fan place on a lower shelf until cooked.
Remove from the tin and cool on a rack. Once cooled, keep in an airtight tin.
If freezing, when cool, double wrap with cling film. Enjoy x.