Preheat your oven to 350°F (175°C).

In a large mixing bowl, whisk together the all-purpose flour, granulated sugar, unsweetened cocoa powder, baking powder, and salt until well combined.

Pour in the water, vegetable oil, and vanilla extract. Stir the mixture until just combined and there are no dry patches. Avoid overmixing to ensure your brownies stay tender.

Lightly grease an 8x8-inch baking pan or line it with parchment paper for easy removal.

Transfer the brownie batter to the prepared pan and smooth the top with a spatula.

Bake in the preheated oven for about 30 minutes, or until a toothpick inserted into the center comes out mostly clean with a few moist crumbs attached.

Allow the brownies to cool in the pan before slicing into squares.