Preheat oven to 350°. Line a 9x9 baking dish with parchment paper or spray with cooking spray.
In a large bowl, combine the flour, salt and baking powder. Set aside.
In another bowl, cream together the sugar and butter. Then mix in the eggs and vanilla until well combined.
Pour wet ingredients into dry ingredients. Stir together with a spatula just until well combined. Then pour half of this batter into the other bowl.
To the first bowl, fold in cocoa powder and chocolate chips.
To the second bowl, stir in pumpkin puree and the spices.
Pour the chocolate batter into the baking dish and spread in an even layer across the bottom. Then pour the pumpkin batter on top and spread in an even layer.
Bake in preheated oven for 45 - 48 minutes, or until a toothpick inserted comes out clean.
Allow to cool to room temperature before cutting and serving. Store brownies covered at room temperature for up to 4 days (not that they will be around that long!)