Cut the butter into small chunks. Put in a medium bowl, add the maple syrup and sugar and cream them all together.
Add the egg and vanilla and blend in.
Add the flour, oats and baking soda and mix well then fold in the chocolate chips.
Lightly butter an 8in/20cm skillet (frying pan), add the batter and spread it out into a flat layer. Bake for approx 15-18 minutes until it looks evenly cooked on top (it should be dry to touch but not look too browned). Best served warm - great topped with ice cream.