Preheat oven to 325 degrees. Grease an 8x8 baking dish with cooking oil. Roughly chop the macadamia nuts; set aside.
In a large bowl combine the brownie mix, applesauce, cinnamon, nutmeg, coconut oil, and only 3/4 cup of the pumpkin puree. Fold the macadamia nuts into the brownie batter. Pour the brownie batter into the prepared pan and spread evenly.
In a medium bowl, whisk the flour and sugar together. In a small heatproof bowl, melt the butter in the microwave for 20 seconds. Add in the melted butter to the flour mixture until it forms into crumbs.
Sprinkle the streusel crumble evenly over the top of the brownie batter in the pan. Bake for 40 to 45 minutes or until a toothpick inserted into the center comes out clean.
Cool completely before cutting. Cut the brownies into 8 equal squares. Enjoy!