Preheat your oven to 375 degrees F. If you don't have buttermilk, make your own by mixing in half a tablespoon of white vinegar or lemon juice to your milk and let it sit for a couple of minutes. Line your muffin pan with baking cups or just grease your pan with oil spray.
If using fresh blueberries, rinse them and remove any stems. Let them drain and pat them dry. (If using frozen blueberries, do not thaw them.)
In a medium bowl, add your wet ingredients (buttermilk, egg, honey/maple syrup, oil, extract). Stir gently to mix. Add in the flour, baking powder, baking soda and salt. Gently stir with a spoon, just until mixed. It shouldn't be completely smooth, or you will have tough muffins. Gently stir in the blueberries.
Using a scoop or spoon, fill the muffin cups about 2/3 full, until you have used all of the batter. Bake for 15-20 minutes, until the tops are browned and a cake tester or toothpick comes out clean when inserted in the center of a muffin. (Check after 15 minutes so as not to overbake them.)
Let the muffins rest for 10 minutes in the pan before transferring them to a wire rack to finish cooling. Store leftover muffins in a plastic container at room temperature for three days, or freeze extra muffins the day they are made.