Preheat the oven to 375°F. Place muffin paper liner in the muffin tin. Optional: coat the muffin tin cups with cooking spray or butter.
In a large bowl: add sugar and butter. Beat until creamy. Add 1 egg to the batter and beat until creamy. Continue with the other egg and beat until well combined. Then pour in the milk, vanilla extract, while continuing to mix.
Once the mix is uniform, add flour, baking powder, salt and combine using a mixer mix. Highly recommend that you sift the dry ingredients before mixing with the wet ingredients to form a smoother batter. This will make the muffins very soft & fluffy (don'tskip this tip)
Mash 2 tbsp blueberries and add to the batter. Use a spatula to mix everything together. Do not use a mixer. Add the rest of the fresh whole blueberries (if using frozen blueberries: do not let thaw, mix in while still frozen) then gently fold the batter until evenly distributed throughout the batter (do not over mix or use a mixer on this step, be gentle).
Use an ice cream scooper to measure even portions. Place each scoop of batter into the muffin tin cup (should be exactly 12 scoops). Sprinkle sugar on top of the batter.
Bake for 28-30 minutes or until golden brown. Let the muffins cool in the tin for about 5 minutes and then transfer them to a baking rack until completely cooled.