When I make oatmeal for a friend, I never know how much of it he is going to eat, and since I don't much like oatmeal myself, don't want to save and reheat it (sorry, but yuck!), and hate to throw away food, I came up with a fairly healthy version of oatmeal cookies that are relatively fast and easy to make. They are not gluten-free because Pillsbury uses white flour in the mix, but the first ingredient is definitely oats and The recipe is quite forgiving, not exact, but I have made it quite a few times in slightly different ways and the cookies always turned out yummy.
The oatmeal I start out with is made with plumped raisins and has cinnamon and a little maple syrup over the top. What is leftover goes in a bowl with an egg, butter or coconut oil, brown sugar, and a pinch of baking soda. I mix that all together and then add a handful of Pillsbury Oatmeal Chocolate Chunk cookie mix from a box. After stirring that in, then I start slowly adding coarse oat flour (I lightly pulse oat flakes in the blender to make the flour) and mixing until the dough is quite stiff.
My photo shows a batch of this cookie mix that I baked in a rectangular pan and cut into bars. I'm munching on one now and although I prefer the cookie shape, either way, these disappear fast. I like being able to control the type and amount of sugar in these cookies.