Pre-heat oven to 350 degrees and spray an 8x8" pan with baking spray.
Sift together oat flour, whole wheat flour, sugar, baking soda, salt and cinnamon into a large bowl.
To your stand mixer add the brown sugar, applesauce, butter and oil on medium speed until creamy.
Add in the eggs, vanilla and yogurt until well blended.
Lower the speed to the lowest setting and add in the dry ingredients until just blended.
Add half the batter to your baking pan.
Top with half the walnuts and gently lay half the blueberries onto the walnuts.
Spoon over the remaining batter gently and top with remaining walnuts and blueberries (gently).
Bake for 30-35 minutes.