Preheat your oven at 325°.
In a bowl, add the butter and sugar, and mix well. Set it aside for a few minutes.
In another bowl, mix the flour, corn starch, and salt, and set it aside.
In the bowl with the sugar and butter, add the eggs, vegetable oil, vanilla, and cocoa powder. Mix until it's all incorporated.
Add the flour mixture by sifting it into the chocolate mixture with the chocolate chips. Mix until there are no clumps.
In an 8 x 8 baking pan, spray non-stick oil spray and line the bottom with parchment paper. Spray the parchment paper as well.
Pour the mixture into the pan evenly.
Bake for 30 minutes, but do not overbake.
Take it out and let it rest for at least an hour or even longer before enjoying.
