Preheat the oven to 350°F.
Lightly grease an 8" round cake pan.
The easiest way to make the dough is in a food processor.
Place all of the ingredients into the work bowl, and process to make a smooth, sticky dough.
If you don't have a food processor, grind the oats in a blender before using.
If you don't have a blender or food processor, use quick oats, rather than traditional. Combine the oats with the remaining ingredients, and mix until smooth.
Press the dough into the prepared pan, and score it into 16 wedges. A knife or baker's bench knife, dipped in water between cuts, works well.
Bake the shortbread for 35 to 40 minutes, until it's firm and golden brown.
Remove it from the oven, and after 5 minutes turn it out of the pan onto a piece of parchment, or a clean work surface.
Cut all the way through the score marks to make wedges.
Place them on a rack to cool completely.
Store shortbread, well wrapped, for up to a week; freeze for longer storage.
The flavor improves as the shortbread ages.