Preheat oven to 350°F and line a baking sheet with parchment paper.
Combine all the ingredients for the blueberry filling except the arrowroot powder in a small sauce pan over high heat. Bring to a boil, stirring frequently to mash the blueberries.
Once boiling, reduce to medium-low and continue mashing blueberries as the sauce thickens and reduces for about 5-7 minutes.
Stir in the arrowroot powder, remove from heat and let cool to thicken.
Combine all the flour and salt in a medium bowl.
Whisk together the coconut oil, applesauce, maple syrup and vanilla in a small bowl.
Add the wet ingredients to the dry ingredients and stir until a wet dough forms.
Roll the dough into balls just smaller than golf ball size and place on the baking sheet.
Gently press down on the balls with your thumb to make and indent in the middle of the cookie for the filling. Use your fingers to press together any cracks around the sides of the cookies after doing this.
Bake for 12-14 minutes until the edges just start to turn light brown.
Remove cookies from the oven, let cool completely then spoon the blueberry filling into the indentation.