01 -
Preheat oven to 350°F (175°C) and grease an 8-inch square baking pan.
02 -
In a bowl, mix together flour, cocoa powder, baking powder, and salt until thoroughly blended.
03 -
In a separate bowl, whisk melted butter and granulated sugar until creamy.
04 -
Add eggs and vanilla extract to the butter-sugar mixture and blend until fully combined.
05 -
Gradually add the dry ingredients to the wet mixture, stirring just until a cohesive batter forms.
06 -
Gently fold in chopped pistachio nuts and, if desired, chocolate chips.
07 -
Pour batter into the prepared baking pan and smooth the top for even baking.
08 -
Bake for 25 to 30 minutes, or until a toothpick inserted in the center comes out with moist crumbs.
09 -
Allow brownies to cool completely in the pan. Cut into squares using a sharp knife and serve.