Preheat oven to 375 degrees.
In a large bowl, cream together the butter and sugar.
Next, mix in the cocoa, vanilla, vegetable oil, and eggs.
Last, add remaining dry ingredients (flour, baking powder, salt) and stir until there are no lumps.
Pour the batter into a well greased 8 x 8 baking dish.
Bake for approximately 15-20 minutes, or until a toothpick inserted in the center comes out clean. Allow the brownies to cool thoroughly before cutting.
Enjoy!