In a small bowl, mix the blueberries, granulated sweetener, and water. Use a fork to gently press the blueberries. Be careful not to mash them but just barely open them up. Place in the refrigerator to macerate for up to 24 hours.
Preheat oven to 350 degrees. Grease a muffin tin or silicone cups.
In a large bowl, combine the almond flour, baking powder, soda, and powdered sweetener. Whisk to combine.
Take blueberries out of the fridge and drain the water. Pat them dry with a paper towel. Take 1 to 2 tablespoons of the dry muffin mix and add to the berries. Toss to coat and set aside,
Add the vanilla, sour cream, and eggs to the remaining muffin mixture. Whisk until fully combined.
Fold in the blueberries.
Divide the batter between 10 muffin cups.
Bake for 20 minutes. Let cool 5 minutes before removing from pan.
Notes
You may skip the macerating step if pressed for time but the berries and/or muffins may not be as sweet. Serve with keto blueberry compote.