In a mixing bowl, combine flour and sugar. Add cold butter and mix until crumbly.

Add egg yolk and ice water, mixing until dough forms. Shape into a disk, wrap in plastic, and refrigerate for 30 minutes.

Preheat the oven to 375?F (190?C). Roll out the dough and fit it into the tart pan.

Prick the bottom with a fork and bake for 15 minutes until lightly golden.

In a bowl, combine blueberries, sugar, cornstarch, lemon juice, and vanilla. Toss gently to coat.

Pour the blueberry mixture into the pre-baked crust.

Bake for an additional 30 minutes until the filling is bubbly and the crust is golden.

Allow the tart to cool before slicing. Serve with whipped cream if desired.