Preheat oven to 350 F. In a small bowl, combine pumpkin, 1/4 cup applesauce and pumpkin pie spice until well blended. In a medium bowl, combine yogurt, 3/4 cup applesauce, both sugars and vanilla until well combined. In a large bowl, whisk flour, cocoa, baking powder and salt together. Add yogurt mixture to flower mixture and combine. Spoon brownie mixture into a greased 8x8 square baking pan. Use a spatula to spread it out evenly. Spoon pumpkin mixture on top, using a spatula to even out smoothly. Then use spatula to swirl and mix the batters together. Bake 45 minutes to 1 hour, or until a toothpick inserted in the center comes out clean. Allow to fully cool before slicing.