Preheat the oven to 400 degrees Fahrenheit.
Cream together the butter and 1 1/4 cups sugar until it becomes light and fluffy, preferably in a stand mixer or with a hand mixer.
Add in the eggs, one by one, making sure you beat well after each addition.
Stir in vanilla, lemon juice, and buttermilk and mix well to combine.
Sift the flour, salt, and baking powder into to the sugar, buttermilk, butter, and eggs. Using a sifter will help to reduce clumping and prevent you from overworking muffins.
In a small bowl, lightly mash/smush about half of the blueberries with the back of a spoon (sort of like muddling mint in a drink) and then stir into the batter.
Fold in the remaining blueberries. We also like to save a couple to drop right on the tops of the muffins.
Line a 6 cup jumbo muffin tin or 12 cup standard muffin tin with cupcake liners.
Fill with batter - leave 1/3 muffin tin/liner for muffins to rise above.
Sprinkle the 3 teaspoons sanding sugar over the tops of the muffins, reduce oven heat to 375, and bake at 375 degrees for about 30-35 minutes.
If you are using regular side muffin tins, only bake 12-15 minutes or until a toothpick comes out of the top of the muffin clean.
Optional: Reserve sanding sugar until end of cooking. In final 10 minutes of baking, brush tops of muffin with melted butter. Top with sanding sugar. Continue baking until cooked until toothpick inserted comes out completely clean.
Remove muffins from tin and cool at least 30 minutes.
Enjoy!