Preheat the oven to 180°C (350°F). Line the springform with baking paper and grease the sides.
Melt the butter and let it cool down for about 5 minutes.
Mix butter, sugar, eggs and vanilla.
Mix flour, cocoa powder, baking powder and salt and gradually stir into the butter mixture.
Put the dough into the prepared form and bake for 20-25 minutes, until a toothpick comes out clean.
Remove the brownie from the pan and let it cool down.