Preheat oven to 160˚C. Lightly grease and line a 20cm square slice tin with baking paper. Cut baking paper larger than the tin so that you have an overhang, making it easier to remove the slice once cooled.
Mix all ingredients thoroughly in a large bowl. Evenly press mixture into lined slice tin.
Cook for approximately 20-25 minutes, until golden and firm. Cool in the tin. Serve cut into bars.