To make the cake:
Preheat the oven to 180C/350F/Gas 4.
Butter the sides of a round cake tin and line the base with greaseproof paper.
Peel and cut each apple into twelve slices.
Arrange them in a single layer on the bottom of the tin and sprinkle the dark brown sugar over them.
Place the butter, light brown sugar, eggs and flour in a large mixing bowl and mix until well combined.
Spoon the cake mixture over the apples and sugar already in the cake tin.
Bake for 40-45 minutes – the cake should be nicely golden and coming away from the edges of the tin.
Allow it to cool in the tin for 5 minutes and then turn onto a serving plate. The apples which were on the bottom of the tin will now be the top of the cake.
To make the fudge sauce:
Put the butter, light brown sugar and lemon juice into a medium sized saucepan. Allow the ingredients to melt over a low heat for a few minutes.
Stir and pour over the cake when it’s cool.