Preheat the oven to 350°F (175°C). Line a baking pan (8x8 inches works perfectly) with parchment paper or lightly grease it. This will ensure your brownies come out easily once they’re baked.
Mix the wet ingredients: In a large mixing bowl, whisk together the Greek yogurt, sugar, eggs, and vanilla extract until smooth and well combined. The Greek yogurt should blend seamlessly with the other ingredients, giving you a creamy base.
Add the dry ingredients: Sift the cocoa powder, flour, baking powder, and salt into the wet mixture. Gently fold them together until they are just combined. Be careful not to overmix; you want to maintain the brownies’ soft, fudgy texture.
Fold in the chocolate chips (optional): If you’re using chocolate chips or chopped chocolate, gently fold them into the batter. This step adds extra richness and texture to your brownies.
Transfer to the baking pan: Pour the brownie batter into the prepared baking pan. Use a spatula to spread it out evenly, making sure the surface is smooth.
Bake for 20-25 minutes. Check for doneness by inserting a toothpick into the center. If it comes out with just a few moist crumbs (not wet batter), your brownies are ready!
Cool and slice: Allow the brownies to cool in the pan for about 10 minutes, then transfer them to a wire rack to cool completely before cutting them into squares.