Preheat the oven to 400°F
In a large bowl, mix together butter and sugar until fully incorporated and granular. This works best with soft butter, you can use a mixer, fork, or handheld pastry cutter. Mix until the texture resembles crumbly brown sugar.
Add the eggs, one at a time, whisking or beating after each egg until creamy. Add vanilla extract, and yogurt and mix until fully incorporated.
In a separate bowl, mix together flour, salt, and baking powder. Add dry ingredients to the liquid mixture, mixing until flour is just incorporated. Do not overmix; the batter should not be smooth.
Fold in the blueberries with a wooden spoon or rubber spatula. It works best to add blueberries in batches for even distribution. Fold in milk last.
Line a 12-cup muffin tin with cupcake liners (or grease tin without liners) and fill with batter to just about the top of each cup. The batter is fairly thick, so do your best to fill the cups evenly. Sprinkle a little sugar over each muffin and bake on the top rack for about 18-20 minutes. Tops of the muffins should be just golden and a toothpick should return clean when pierced in the center.
Remove muffins from the tin and let cool for 15-20 minutes before serving.