Grease and line your cake tin, I used a loaf liner in my 2 lb loaf tin.
Weigh out the flour, butter and sugar and place in a large bowl. Rub the ingredients together with your fingers, like making crumble, until you have the texture of fine breadcrumbs.
Grate your apple into a bowl using a cheese grater, and mix it into the eggs and orange extract.
Stir the apple and egg mixture into the flour and butter mixture, and mix until just combined.
Add about three quarters of the redcurrants and mix in.
Scrape the cake batter into your tin and spread it out.
Spread the remaining redcuarrants on top and press them in lightly. Remember to keep a few back to decorate the cake with.
Bake at 180 degrees for around 45 minutes, until lightly brown and a skewer in the centre comes out clean.