Flour, sugar, and salt are combined in a small bowl. Once the mixture is crumbly, add butter. Vinegar should be added and moistened by forking. A lightly greased, 9-inch tart pan with a detachable bottom should be pressed into the bottom and up the sides.

In a dish, lightly mash two cups of blueberries to make the filling. Blueberries are stirred into the sugar, flour, cinnamon, and nutmeg mixture. Sprinkle 1 cup of the remaining whole blueberries over the mixture after spreading it evenly into the crust. Put the baking sheet on top of the tart pan.

Bake for 40–45 minutes at 400 degrees Fahrenheit, or until the crust is golden brown and the filling is bubbling. After removing from the oven, top with the remaining berries. Let cool on a wire rack. Place in the fridge to store.