Preheat the oven to 375°F (190°C).

In a mixing bowl, combine the fresh blueberries, ½ cup of sugar, cornstarch, lemon juice, vanilla extract, and salt; stir gently to coat without crushing the berries.

Place the prepared tart crust into the 9-inch tart pan, pressing it firmly into the edges.

Spoon the blueberry mixture into the tart crust and spread evenly.

Sprinkle the remaining ¼ cup of sugar over the blueberry filling.

Bake in the preheated oven for 35 minutes, or until the filling bubbles and the crust is golden brown.

Remove from the oven and let cool on a wire rack for at least 30 minutes to allow the filling to set.

Slice into wedges and serve, optionally topped with whipped cream or a dusting of powdered sugar.