Preheat the oven to 350°F. Line a 9x13-inch baking dish with parchment paper, including up the sides of the dish.
In a large bowl add flour, cocoa, baking powder, and salt. Whisk together ingredients until they are fully incorporated.
In the bowl of a stand mixer or in a large bowl using a hand-held mixer, beat the eggs, sugar, butter, and vanilla until light and fluffy.
With the mixer off, add the flour mixture to the wet mixture. Turn mixer on low and mix until ingredients are well combined.
Pour brownies into the lined baking dish and bake for 30-35 minutes. Brownies are done when an inserted toothpick is removed with crumbs but no wet batter.
With about 10 minutes left in baking the brownies, make the ganache.