Preheat the oven to 325F.
In the bowl of a heavy-duty stand mixer, cream together butter and sugars until light and fluffy.
Add in the egg, mixing till well-incorporated, then add the oil, mixing till well-incorporated.
In a medium bowl, mix together flour, cocoa, salt, and baking soda (plus cinnamon, if using), whisking till combined.
Add the dry ingredients to the wet ingredients, mixing till incorporated. With the mixer on low, add in the oats, corn flakes, coconut, chocolate chips, toffee bits, and pecans.
Using a cookie scoop or a tablespoon, drop walnut-sized lumps of dough on a parchment-lined cookie sheet.
Flatten the cookies slightly using a fork dipped in water. Bake for 12-15 minutes.