In a stand mixer or by hand, cream together the butter and white and brown sugar until smooth. Add in the egg and vanilla extract, mixing till incorporated.
Sift together the flour, cinnamon, salt, baking soda, and oats in a separate bowl. Combine the dry and wet ingredients and stir till just combined.
Gently mix in the walnuts, chocolate chips, and chopped candy bar.
Roll heaping tablespoons of dough and place on a parchment paper-lined baking sheet. Bake for 9-11 minutes or until cookies are golden brown. Don't over bake! They will finish baking outside of the oven.
Recipe by at https://www.ideahacks.com/double-chocolate-chunk-oatmeal-cookies/