INGREDIENTS
2 cups
all-purpose flour
1/2 cup
unsweetened cocoa powder
1/4 cup
(packed) brown sugar
2 tsp
baking powder
1 tsp
baking soda
1 tsp
kosher salt
3
large eggs, separated
2 cups
buttermilk
1/2 cup
olive oil
1 tsp
vanilla extract
6 oz
bittersweet chocolate (at least 70% cacao), finely chopped
Nonstick vegetable oil spray
Unsalted butter and warm pure maple syrup (for serving)