Prepare the pastry by mixing the flour and powdered sugar in a bowl. Add the chilled, cubed butter and rub it into the dry ingredients until the mixture resembles breadcrumbs. Add the egg yolk, mixing until the dough comes together. Roll out the dough on a lightly floured surface and cut out circles to fit your muffin tin. Line the muffin tin with the dough circles and chill while you make the filling.

In a separate bowl, prepare the filling by whisking together the Pudding Suprême French Vanilla, eggs, granulated sugar, milk, and vanilla extract until smooth and well combined. Make sure there are no lumps in the mixture.

Pour the filling into the chilled pastry shells, filling each one almost to the top. Preheat your oven to 180°C. Bake the tarts in the preheated oven for 15-20 minutes, or until the filling is set and the pastry is golden brown. Allow the tarts to cool for a few minutes in the tin before transferring them to a wire rack to cool completely.