In a mixing bowl, add the flour, salt, baking powder, and cinnamon. Mix well and set aside.
In another mixing bowl, add the brown sugar, oil, eggs, and vanilla. Whisk on high until sugar is dissolved and mixture is incorporated.
Gradually add the dry ingredients while whisking.
Once batter is smooth, using a paddle, incorporate the sourdough discard until you no longer see streaks.
Gently fold in 1 1/2 cups of blueberries.
Divide the batter into generously oiled mini loaf pans.
Top the loaves with the remaining blueberries, pressing in slightly. Optional decoration sugar if you like.
Set the loaf pans in the air fryer basket leaving some room between the pans for air flow.
Cook in the air fryer at 320° for about 20 minutes. Rotate the pans halfway, for even cooking.
Once loaves are fully cooked, testing with a toothpick, remove the pans and let cool to touch before removing the loaves from the pans.
Enjoy!