Preheat oven to 350°F. Line a 9x9-inch pan with foil and spray with nonstick cooking spray.

Place oil in a large bowl. Stir in sugar and cocoa powder until smooth using a wooden spoon.

Add eggs, vanilla, and salt, stir to combine, then slowly mix in the flour. Batter will be thick. Spread batter into prepared pan.

Bake for 21-25 minutes or until the brownies just lose that glossy sheen around the edges and a toothpick inserted 1-inch from the edge comes out clean. Cool completely before topping.

Finely crush Oreo cookies in a food processor. Remove 2 tablespoons crumbs for topping. Add cream cheese to food processor and pulse until mixture is combined and smooth, scraping down the sides of the machine as needed. Spread over brownies and press to compact.

Melt chocolate chips and oil in a microwave safe bowl (on high in 30 second increments, stirring between each, until melted and smooth). Spread evenly over Oreo truffle mixture using an offset spatula. Sprinkle with Oreo cookie crumbs. Chill to set before slicing into bars.