Set your oven to 350°F (175°C). Grease or line an 8x8-inch square baking pan with parchment paper for easy removal.
In a medium mixing bowl, whisk together Greek yogurt, melted coconut oil (or butter), maple syrup (or honey), eggs, and vanilla extract until smooth.
Sift in cocoa powder, flour, baking powder, and salt. Gently fold the mixture until just combined—avoid overmixing to keep the brownies tender.
Fold in the chocolate chips, distributing them evenly throughout the batter.
Transfer the brownie batter to the prepared baking dish. Use a spatula to spread it evenly, then sprinkle extra chocolate chips on top for a bakery-style finish.
Place the pan in the preheated oven and bake for 20–25 minutes, or until the center is just set. A toothpick inserted should come out with a few moist crumbs—this ensures fudgy brownies.
Let brownies cool completely before slicing. This helps them set and develop their full flavor.