1. Preheat oven to 180ºC (350ºF) and grease a 20-cm (8-inch) square glass pan.
2. In a medium-sized mixing bowl combine the cornflour, cocoa powder, cinnamon, and salt. Whisk by hand until well blended.
3. Place butter, sugar, vanilla, and eggs into the Vitamix container in the order listed and secure lid.
4. Select Variable 1.
5. Turn machine on and slowly increase speed to Variable 10, then to High.
6. Blend for 35 seconds or until well blended.
7. Pour mixture into dry ingredients, add chocolate chips and walnuts and stir together to combine.
8. Pour batter into prepared pan and bake for 30-35 minutes or until a toothpick inserted in center comes out clean.
9. If desired, dust brownies with powdered sugar prior to serving.
Notes: When checking for doneness, because of the melted chocolate chips the toothpick may not come out clean. To tell if brownies are done, top should be firm to the touch and sides should be just beginning to turn crisp.
Recipe from Vitamix Australia.