Preheat oven to 350 degrees and grease a 12 muffin tin.
In the jar of a blender, blend all liquid ingredients until smooth.
In a large mixing bowl, whisk the dry ingredients (minus the blueberries)
In a separate bowl, toss the blueberries with a couple of tablespoons of the flour mixture until they are evenly coated (this helps them float in the batter as opposed to sinking).
Fold the liquid into the dry just until mixed. ***Take stock of the batter. With different brands of almond flour and cassava flour out there, there CAN be variability in liquids absorbed. If it seems overly thin, then add a bit of any of the above flours until a typical muffin/cake batter is achieved.
Then gently fold in the blueberries.
Distribute batter to muffin cups, filling 2/3 of the way.
Bake for 20-25 minutes until the tops are set. ***if you are using frozen blueberries, this will effect the final cooking time, more like 25 minutes instead of 20!