Preheat your oven to 180C / 350F / Gas mark 4 and line a 9x9 inch tin with parchment paper or lightly grease is.
Add the flour, cocoa, both sugars, both lots of chocolate chips, pecans and raisins to a large mixing bowl and give them a good mixing together.
Add the vanilla extract, vegetable oil and eggs and mix till everything is just combined.
Pour the batter into a lined tin, smooth it out so it reaches every corner and pop it into your oven for 20 to 25 minutes.
Check your brownies after 20 minutes if you have a quick oven, you want a slight wobble in the middle but an over all set feeling.
Take them out of the oven and allow the to fully cool down.