Preheat the oven to 350°F. Lightly grease a 6-cup muffin pan or use a silicone muffin pan.
In a medium bowl, mix together the coconut flour, baking powder and sweetner.
Make a well in the center. Crack the eggs into the well and beat lightly.
Add sour cream and make a smooth batter.
Gently fold in blueberries.
Scoop the batter into mini muffin cups (makes 16) or standard muffin cups (makes 6). Fill the muffin cups almost full, as these to not rise as much as normal muffins.
Bake the muffins for about 20-25 minutes until the tops have browned. Let them cool for about 5 minutes in the pan, then transfer them to a rack to cool.