Place blueberries in a 9 inch pie plate or glass baking dish. Add applesauce, vanilla, and coconut sugar and mix carefully to coat blueberries. Let stand a few minutes, then mix in arrowroot.

Preheat oven to 350°F. Whisk together eggs and coconut oil in large bowl. Combine coconut flour, almond flour, salt, baking powder and coconut sugar in separate bowl, then stir into egg-oil mixture.

Pour batter over blueberry mixture, spreading to edges of pan if necessary. Bake 25 to30 minutes, or until lightly browned on top and toothpick inserted in middle comes out clean. Cool 10 to 20 minutes and serve warm. Or for a sweeter cobbler, allow to cool completely, cover with plastic wrap, refrigerate, and serve cold.