Preheat your oven to 350°F (175°C). Line an 8x8-inch baking pan with parchment paper.
In a mixing bowl, whisk together the olive oil, caster sugar, and brown sugar until well combined.
Add the eggs one at a time, whisking until fully incorporated.
Sift in the cocoa powder and flour, then gently fold the mixture until just combined.
Stir in the chocolate chips.
Pour the batter into the prepared baking pan and spread it evenly.
Bake for 22-25 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs.
Let the brownies cool in the pan for at least 30 minutes before slicing and serving.