1- Dissolve the yeast in lukewarm milk and let it sit for 10 minutes.
2- Work the flour, thawed yeast, sugar, vanillin, egg yolk and salt. Add in the butter chunks. Work the mix until you get a homogeneous dough with shiny and non-sticky surface.
3- Roll out the dough with a rolling pin. Place it in the greased and floured tart pan and make several holes with a fork.
4- For the garnish, beat the eggs and icing sugar until white. Add the ground walnuts and melted and cooled butter.
5- Pour the garnish over the dough. Bake it in a oven preheated at 200 °C for about 20 minutes and let it cool down.
6- For the caramel, melt the sugar on low heat until caramelized. Add in the cream, vanillin and butter.
7- Put the walnuts in circles around the edge of the baked tart and sprinkle in the centre. Pour the caramel in circles over it. You can sprinkle icing sugar as you wish.
