Use a wooden spoon or spatula to mix very well, until the dry ingredients are well mixed and everything has been incorporated.
Transfer the mixture into the prepared baking tin. Press down firmly, using a lightly dampended hand, to make an even layer.
Bake for 30-35 minutes, or until the edges are lightly golden. Remove from the oven and cool fully at room temperature before transferring to the refrigerator to chill before slicing.
Store in the refrigerator or freezer. The bars are best kept cool.