Preheat your oven to 180°C (350°F) and line an 8x8 inch baking tray with parchment paper.
In a large bowl, whisk together flour, cocoa powder, sugar, baking powder, and salt until well combined.
Add melted butter (or oil), milk, and vanilla extract. Mix until a thick, smooth batter forms.
Stir in hot water or coffee to enhance the chocolate flavor and improve texture.
Pour the batter into the prepared baking tray and spread evenly.
Bake for 25–30 minutes, or until the top is set but the center still feels slightly soft.
Let the brownies cool completely before cutting into squares for the best fudgy texture.