Preheat the oven to 375 degrees. Prepare a muffin tin with cupcake liners spritzed with nonstick cooking spray.
In a large bowl, combine the flour, sugars, baking powder, cinnamon, and salt. Stir in the blueberries. Create a well in the center of the flour mixture and set it aside.
In another bowl, whisk the eggs until foamy. Add the milk, melted butter, and vanilla, mixing until blended. Stir in the apple.
Add the wet mixture to the flour mixture all at once. Stir just until the ingredients are moistened; the batter should be lumpy.
Divide the batter evenly between the 12 prepared muffin cups, filling each one almost to the top. Top with Coarse turbinado sugar if desired.
Bake for 18 to 20 minutes, or until the muffins turn golden and a wooden toothpick inserted into the centers comes out clean.
Allow the muffins to cool in the muffin cups on a wire rack for 5 minutes. Then, remove them from the muffin cups and serve them warm.