Preheat your oven to 350 F (177 C). Line a baking sheet with parchment paper or a silpat.
In an electric stand mixer fitted with the paddle attachment, cream your brown sugar, butter, oil and granulated sugar on medium speed until fully incorporated. Add the eggs + vanilla and mix on medium until everything is well blended.
In a medium bowl whisk together all-purpose flour (or white whole-wheat flour), bread flour, baking powder, baking soda and sea salt.
Dump the flour mixture into the electric stand mixer and mix on low until the cookie dough is barely blended. You still want to see streaks of flour. Take the bowl out of your stand mixer and fold in the Halloween candy until just mixed. (Side Note: You can put the dough, wrapped tightly in plastic wrap, in the fridge for several days at this point, if you want to make the cookies another day. Additionally, you could also roll the dough into balls, freeze in a single layer on a cookie sheet and then shove them in a resealable plastic bag and put back in the freezer to have cookies on-demand...just add a minute or two to the bake time.)
Roll into balls of about 2 tablespoons each and allow about 2 inches of space between the dough balls.
Bake the cookies in the center of the oven for about 12 minutes. Fresh out of the oven, sprinkle with the sea salt flakes. Allow to cool on the baking sheet for 5 minutes post baking and then move to a cooling rack to finish cooling down.
You're done. They're a revelation, am I right?