Preheat your oven to 375°F (190°C) and line a baking sheet with parchment paper.
In a large mixing bowl, combine the flour, granulated sugar, baking powder, baking soda, salt, and ground cinnamon. Whisk until well blended.
In a separate bowl, whisk together the buttermilk, egg, vanilla extract, and melted butter until smooth.
Pour the wet ingredients into the dry ingredients and gently stir until just combined. Be careful not to overmix; a few lumps are okay.
Fold in the fresh blueberries, ensuring they are evenly distributed throughout the batter.
Using a tablespoon, drop spoonfuls of the batter onto the prepared baking sheet, spacing them about 2 inches apart.
Bake in the preheated oven for 15-18 minutes, or until the fritter bites are golden brown and a toothpick inserted in the center comes out clean.
Allow the fritter bites to cool for a few minutes on the baking sheet before transferring them to a wire rack to cool completely.
If desired, dust with powdered sugar before serving.