Preheat the oven to 180℃, line a baking tray with baking paper and set aside. In a small mixing bowl add the flour, corn flour, cocoa powder, baking powder, baking soda, cinnamon powder, chili powder, salt and stir together, set aside.
In a large mixing bowl add the softened butter, olive oil and beat until soft and pale. Add the sugar and beat again using an electric beater, alternatively you can use a rubber spatula or wooden spoon. Once creamed together, add the eggs and vanilla, beat until smooth.
Add the dry ingredients and mix until combined. Add chocolate chips or chopped dark chocolate chunks and stir well. In a plate add the ingredients for the spiced sugar, i.e. sugar, cinnamon powder, chili powder and stir.
Using an ice cream scoop, portion the cookie dough and roll into the spiced sugar mix. Place on the baking tray and stud the top with more chocolate chips.
Bake for 9-12 mins until they are cracked on top and risen. Using a metal spatula, transfer the cookies to a wire rack.