200g digestive biscuits
For the filling
150g unrefined light muscovado sugar
1/2 x 397g can Carnation Condensed Milk
100g good-quality plain chocolate, broken up
50g pecans, toasted and roughly chopped
1. Whizz the digestive biscuits in a food processor until finely ground. Melt the butter in a saucepan and stir in the ground biscuits. Mix well. Tip into a 20cm loose-bottomed fluted flan tin and, using the back of a dessertspoon, press into the base and up the sides to make the biscuit casing. Chill for 30 minutes in the fridge until set.
2. Make the filling. Put the butter and muscovado sugar into a saucepan over a gentle heat and stir until dissolved. Add the condensed milk and bring to the boil over a gentle heat, stirring continuously. Stir for 2-3 minutes to make a golden caramel. Pour into the tart case and chill for 1 hour in the fridge.
3. Put the plain chocolate pieces into a heatproof bowl over a pan of simmering water to melt, making sure the bowl is not touching the water. Leave to cool until slightly thickened. Spoon the chocolate into a sandwich bag and snip off the corner, then quickly drizzle in zig-zag lines over the tart. Sprinkle the tart with the chopped pecans and leave the cake to set in a cool place for 1 hour.