Break up chocolate and melt in a basin over hot water, not boiling.
Grease and line a shallow swiss roll tin about 32 x 22cm.
Pour in the chocolate and leave to set overnight in fridge.
Preheat the oven to 150c / 300F Gas mark 2.
Cream butter and sugar until light a fluffy.
Add beaten egg, Quaker Oats and fruit.
Mix well and spread evenly over the chocolate.
Bake for 45 mins or until golden brown.
Remove from oven and mark into slices.
Leave until quite cold before removing from tin.