Preheat the oven to 350°F/180°C. Grease an 8 x 8 or similar size pan, line with parchment then grease parchment paper.
In a large bowl, beat the oil, vanilla and both sugars until well mixed. Add the eggs, one at a time, beating after each until completely blended. In a medium bowl, whisk together the flour, cocoa and salt. Stir into the egg mixture, mixing until all flour is stirred in. Add 3/4 cups of the chocolate chips and gently stir to combine. Scrape into the prepared pan. Smooth with a spoon and sprinkle remaining chocolate chips evenly over the top.
Bake on center rack of preheated oven for 20 to 23 minutes, until toothpick inserted in the center comes out mostly clean. Do not overbake or the edges will become hard. Cool brownies in pan on a wire rack. Cut into squares.