Start by gathering all your ingredients and preheating your oven to 375 degrees F (190 degrees C).

In an 8-inch square baking dish, combine the fresh blueberries with the orange juice and 3 tablespoons of white sugar, mixing well to coat the berries evenly.

In a small bowl, whisk together the all-purpose flour, baking powder, and a pinch of salt. Set this mixture aside for later use.

In a large mixing bowl, cream together the softened butter and ½ cup of white sugar until the mixture becomes light and fluffy. Beat in the egg and vanilla extract, ensuring they are well incorporated. Gradually fold in the flour mixture, stirring just until the ingredients are combined.

Using a spoon, drop dollops of the batter over the blueberry mixture in the baking dish, trying to cover as much of the filling as possible.

Place the dish in the preheated oven and bake for 35 to 40 minutes, or until the topping turns a golden brown and the filling is bubbling.

Once done, remove from the oven and allow it to cool slightly before serving. Enjoy your delicious homemade blueberry cobbler!