Oatmeal Cookies

Chop the oatmeal fine using a hand mixer/food processor/a knife if you're really really patient. The finer the oatmeal, the less chunky the texture of the cookies.
Add all other ingredients to the oatmeal, knead until well-combined.
Add any extra ingredients such as raisins, dried cranberries, hazelnuts, etc. Knead until well-combined.
Let dough rest in the fridge for an hour.
Preheat oven to 170 °C
Shape the cookies. Roll a little ball of dough between your hands, then painstakingly flatten it out, making it as thin as possible. Dough is slightly sticky, straight up squishing it in between your palms is not recommended. Intead, use your fingers.
Bake for 13-18 minutes.
Let cool until you're able to handle them, enjoy.

This recipe makes thin, crunchy cookies. I assume the recipe could also work for thicker, chewier cookies if you make the cookies thicker, but I haven't tested this myself.
Rest helps the cookies gain more flavor and makes the dough less sticky, but they'll still taste just fine without the rest period. If you don't want to bother, just don't.
Dough can be stored in the fridge for several days.