Preheat the oven to 375F (190C). Get your 12-cup muffin pan ready by either greasing it or using paper liners.
Grab a large bowl and mix the sugar, oil, eggs, and lemon zest together. Give it a good whisk until everything's nicely combined.
In a separate bowl, combine the flour, baking powder, and baking soda.
Now, take the flour mixture and add it to your egg mixture bit by bit. Do this in two or three rounds, adding buttermilk between each round. Stir each time you add something, but remember, don’t mix too much.
Next, fold in your blueberries. If they’re frozen, just add them as they are – no need to thaw.
Gently stir everything until it’s just combined. Be careful not to overmix!
Time to fill the muffin cups. Spoon your batter into the cups, filling them about three-quarters full. Sprinkle a bit of sugar on top of each muffin for a sweet touch.
Place the tray in the oven and bake for 20-25 minutes. You’re looking for a light brown color on top.
Remove muffins from the oven and let them rest in the pan for 5 minutes. Transfer to a wire rack to cool.