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

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

In a separate bowl, toss apricots with sugar, lemon juice, cornstarch, and vanilla extract.

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

Pour the apricot mixture into the crust and spread evenly.

Bake for 35-40 minutes until the apricots are tender and the crust is golden.

Allow to cool before serving.