Preheat the oven to 180C/350F/gas mark 4
Use a 23cm/9 inch cake tin.
Cream the margarine and sugar together until light and fluffy. Sieve together the flour and baking powder in a separate bowl. Fold in the sieved flour and the ground hazelnuts. Add the orange juice, reserving 3 tbs. for the filling. Place half this cake mixture into the greased, lined cake tin. Finely grind the banana chips. Add the reserved orange juice, rind and cinnamon and mix well. Spread this mixture evenly over the cake batter in the tin. Place the remaining half of the cake batter on top and smooth over.
Bake for 1-1 1/2 hours. Test with a warm knife. Turn out to cool on a wire rack.
