Preheat oven to 425 degrees.
Combine the dry ingredients in a medium bowl - flour, baking powder, and salt.
On low-medium heat, melt butter in a small pot. Do not let the butter brown.
In a large bowl, combine sugar and butter.
Use an electric mixer and cream the butter and sugar until creamy... takes about 2-3 minutes.
Add the wet ingredients - milk, yogurt, vanilla extract, and egg.
Blend for a couple of minutes until all the ingredients are well-combined.
Add all the dry ingredients to the wet.
Mix until well incorporated, however do NOT over mix.
This is how your batter should look.
Take fresh blueberries that have been rinsed and dried. Add a tbsp of flour and mix. This prevents the blueberries from sinking to the bottom of the muffin.
Add the floured blueberries to the batter and fold them in (do NOT mix, FOLD).
The muffin batter is ready.
Using an ice-cream scoop, scoop the batter into a cupcake or muffin tray that has been greased with coconut oil (or any oil you prefer).
Into the oven at 425 degrees for 10 minutes.
After 10 minutes, lower the oven temperature to 375 degrees and bake the muffins for another 10 minutes at 375.
Muffins are ready!