Preheat oven to 375℉.
Use some butter to grease two 6-Muffin trays.
Using an electric mixer, cream together softened butter, lemon zest and honey until pale and fluffy.
Add egg and vanilla extract and continue mixing on medium.
Reduce speed to low and add milk.
In a separate bowl, whisk together flour, baking powder and salt.
Gradually add flour mixture to the batter while mixing it on low speed.
Using a rubber spatula, gently fold in the blueberries just until incorporated.
Fill each muffin only about halfway in order to evenly distribute the batter between them. (NOTE: These do make smaller muffins, but I prefer to have more instead of only 6-8 gigantic ones. It also reduces the bake time)
Bake muffins for about 22 minutes. Check them starting at 20 minutes with a toothpick until it comes out clean. If you're using small muffin trays or frozen blueberries, see notes for baking.
Let the muffins cool for at least 10 minutes before you try to get them out. This recipe is a little crumblier than some others, so if you try too early it'll make a mess. Once cooled, they should come out easily.