Preheat your oven to 350°F (175°C).

In a microwave-safe bowl, melt the unsalted butter and let it cool slightly.

In a mixing bowl, whisk the melted butter with the granulated sugar until combined. Add in the eggs, one at a time, followed by the vanilla extract.

In a separate bowl, sift together the cocoa powder, flour, salt, and baking powder. Gradually add the dry mixture into the wet ingredients, stirring until just combined.

Fold in the semi-sweet chocolate chips.

Grease an 8×8 inch baking pan or line it with parchment paper. Pour the brownie batter into the prepared pan and spread it evenly.

Place the pan in the preheated oven and bake for 20-25 minutes until set around the edges but slightly soft in the center.

Let the brownies cool in the pan for about 10 minutes before cutting them into squares.

Serve warm or at room temperature.