Put the oil and the honey into a saucepan and heat gently until the honey has melted. Remove from the heat and stir in all the remaining ingredients.
Press the mixture into a greased 28cm x 18cm (11" x 7") baking tin and level the top.
Cook in the oven for 20-25 minutes at Gas Mark 4, 180°C, 350°F, until the biscuit is golden brown. Mark it into bars while it is still hot. Cool slightly, then cut into slices. Remove from the tin and cool on a wire rack