Heat oven to 150C/130C fan/gas 2.
Place the sugar, butter and golden syrup
together in a saucepan and gently heat
until the butter has melted, stirring
occasionally. Take the saucepan off
the heat and stir in the oats, mixing
thoroughly. Pour the mixture into a lined
and lightly greased 22cm square tin,
pressing it out evenly using the back of
a wooden spoon. Bake in the centre
of the oven for 40-45 mins.
Allow the mixture to cool in the tin
for 10 mins (or for best results, leave to
cool completely overnight), then evenly
spread over the caramel. There can be discrepancies between the thickness of caramel, and the more you stir the runnier it gets. If it looks too thin pop it into a pan and boil for a few minutes, stirring. Then leave to cool - it should be thicker. Chill until firm.
Melt the chocolate in a heatproof bowl
over a pan of barely simmering water,
then stir in the oil and pour over the
chilled caramel flapjack base. Let the
chocolate set, then cut into squares.
Setting chocolate on top of something squidgy can make it difficult to cut, this is why the oil is added.