Oatmeal Cookie Brittle

1 cup butter, melted and cooled (no substitutes)
1 cup white sugar
1/2 cup packed brown sugar
1 egg
1 1/2 teaspoons vanilla
3/4 cup flour
1/2 teaspoon salt
2 cups rolled oats (or quick-cooking)
1/4 cup semisweet mini chocolate chips

Set oven to 350°.
Stack two large baking sheets together (one inside the other) then line the top one with parchment paper.
In a large mixing bowl beat melted butter with both sugars and vanilla.
Add in egg; beat until combined.
In a small bowl mix together the flour, salt and oatmeal; add to the butter mixture; mix well to combine (the dough will be loose!).
Add in the chocolate chips; mix to combine.
Spread out on top of the parchment paper to about 1/2-inch thick (or as best and as thin as you can).
Bake middle oven rack for about 17- 20 minutes or until set and dry (it might be a bit wobbly underneath but it will set after it cools).
Cool well then cut or break into pieces.