First, preheat oven to 400 degrees F.
In a bowl combine flour, baking powder, baking soda and salt. Set aside.
In a separate bowl beat together butter and sugar until light and fluffy. Add eggs one at a time, scraping down the bowl after each egg, making sure they are combined well.
Add half the liquid mixture to the dry ingredients, stirring by hand until just combined.
Next add in half the buttermilk and all of the lemon juice, stir until just combined.
Then add in remaining flour, stirring until just combined. Follow with remaining buttermilk, stirring until just combined.
Fold in blueberries, mixing until just combined. Do not over-mix or as a result muffins may be tough. Batter will be thick and may be a bit lumpy.
Scoop batter by quarter cups into a 12 count muffin pan that has been lined with paper liners or greased. Each muffin cup will be quite full.
Bake for approximately 20 minutes or until a toothpick inserted into the center comes out clean.
Remove from oven and allow to cool slightly.
Finally, if topping with lemon glaze, mix powdered sugar and lemon juice until well combined, then drizzle over muffins. Enjoy!