Preheat the oven to 350°F. Line a 9x9-inch baking dish with a parchment paper sling. Spray the lined baking dish with baking spray (Baker’s Joy or a generic version). Set it aside.
Using a small mixing bowl, whisk together the flour, cocoa powder, and salt. Set it aside.
Using a medium-sized heat-safe mixing bowl, combine the dark chocolate chips and butter. Microwave for 1 minute, stir, heat in 15-second intervals until the mixture is melted and smooth.
Add the brown and white sugars to the chocolate mixture, and continue stirring until incorporated.
Stir in the eggs, one at a time, until no egg streaks are visible.
Stir in the vanilla.
Stir in ½ of the flour mixture at a time. Stir just until all the flour mixture is added, and do not overmix.
Spoon ½ of the brownie batter into the prepared pan. Spread the batter to the edges of the pan.
Evenly place the unwrapped and halved Rolos over the batter.
Spoon and spread the remaining batter over the top of the Rolo layer. Bake for 25-30 minutes, until a toothpick inserted comes away clean.