Preheat the oven to 400℉/205℃. Line a muffin tin with 12 liners and set aside.
In a medium-sized bowl, add the flour, baking powder, baking soda, and salt. Mix together and set aside.
2 cups all purpose flour, 2 tsps baking powder, 1 tsp baking soda, 1/4 teaspoon salt
In a large-sized bowl, add the white sugar and lemon zest. Using your fingers, rub them together for 2 minutes. This is going to release the lemon oils and fragrance.
1 cup white sugar, 1 tbsp lemon zest
In the same bowl, add oil, eggs, sour cream, vanilla, and lemon juice. Whisk together until combined and smooth.
1/2 cup oil, 2 large eggs, 2 tsps lemon juice, 2 tsps vanilla, 1 cup sour cream
Add in the dry ingredients and using a spatula, slowly fold until a soft muffin batter forms. Mix until JUST combined.
In the bowl with the blueberries, add 1-2 tsps of flour and gently toss around until evenly coated. This will help them not sink to the bottom as they bake.
1 1/4 cups fresh blueberries
Add the blueberries and mix in a few times. Don't over-mix.
Evenly divide the batter between the muffin liners.
Sprinkle streusel on top.
Bake the muffins at 400°F for 15-17 minutes. The muffins are ready when a toothpick inserted comes out dry with no wet batter.