Preheat the oven to 350°F. Lightly grease a 8x8 baking pan or line with parchment paper and lightly spray with cooking spray.
Mix sugar, cocoa powder, flour , instant espresso powder, salt and baking powder together in a large bowl and set aside.
Whisk together eggs and vanilla in a separate bowl. Add to dry ingredients and stir until just mixed
Add melted, cooled butter until just mixed together.
Fold in chocolate chips.
Pour into the prepared pan. Add extra chocolate chips if using. Bake in a preheated oven for 20 minutes or until baked in the centre. You can check the brownies with a fork or toothpick, if it comes out clean, the brownies are ready.
Remove from the oven and cool in the pan on a cooling rack.
Cut into squares and serve.
Store in an airtight container for up to a week, or freeze for up to one month.
