Makes approx 20 cookies
1) Place the egg yolk, orange zest and butter in a food processor and blend. Scrape down the mixture from the sides of the bowl so that the mixture is evenly combined. Add the sugar, flour and oatmeal and blend to a smooth, thick paste.
2) Lightly flour your surface so your dough does not stick. Turn the dough out onto the surface and shape it into a log shape (approx 15cm long). Wrap the log in clingfilm and chill it for 1 hour in the fridge.
3) Cut the log into thin slices. For the slices that you decide to freeze, lay them on a lined baking sheet and place in the freezer to flash freeze. Freeze them for about 4 hours (or overnight). Take the frozen slices and place in a zip lock bag writing the date on the bag. These slices can be frozen for up to 6 months.
4) To bake the cookies, preheat the oven to 180°C. Line a baking sheet with baking parchment.
5) Place the cookies on the prepared baking sheet and bake them in the oven. For non frozen cookies bake for approx 12 minutes. For frozen cookies bake for approx 14 minutes. Cook the cookies until they are golden around the edges. They can burn easily so keep an eye on them throughout the cooking time. Once baked transfer them to a wire rack to cool. Store in an airtight container for up to 3 days.