Preheat oven to 350 degrees. I recommend (after I did this video) to line the pans with parchment paper.

In a saucepan, melt butter and brown sugar until combined. Add vanilla, remove from heat. Add egg, flour and oatmeal.

Spoon 1 Tbsp of batter onto the cookie sheet, using the back of a spoon, spread out until the cookie is in a very thin circle, the oats need to be in a single layer. Don’t crowd them, they spread.

Bake for 8-9 minutes until cookies are golden brown, I placed mine in the freezer for 10 minutes for easier removal from my pan since I did not use parchment paper.