Preheat oven to 350°F (175°C). Grease a 9x9-inch baking pan.
In a medium-sized saucepan, melt the butter over low heat. Remove from heat and stir in the sugar.
Add the eggs and vanilla extract, and mix until well combined.
In a separate bowl, mix together the cocoa powder, baking powder, salt, and flour. Add to the butter mixture and stir until all the ingredients are combined.
Pour the batter into the prepared baking pan. Bake for 25-30 minutes, or until a toothpick inserted into the center comes out clean.
Allow the brownies to cool before cutting into squares.
Interesting Facts
Brownies were first created in the United States in the late 19th century.
Brownies are traditionally made with chocolate, but can also be made with other flavors such as peanut butter and even pumpkin.
Brownies are a popular dessert around the world and are often served with ice cream or whipped cream.