Preheat oven to 350° F or 176 C and greased 8-inch square baking pan
In a medium bowl, combine applesauce, sugar, and vanilla.
In another bowl, whisk together flours, cocoa, baking powder and soda.
Make a well in the center and add wet ingredients; mix until just combined
Gently fold in walnuts and blueberries
Spread mixture into prepared pan and bake for 25 to 30 minutes, until center is firm and not sticky.
Let cool completely before slicing.