Difficulty:[usr 2]
Mix with your fingertips and crumble the butter into the flour.
Make a fountain, put the whole egg, cold water, salt, baking powder in it. Quickly roll into a ball.
Leave to rest for 1/2 hour in the refrigerator to make the dough firmer.
Roll out the dough to 1/2 centimeter thick. Line a lightly buttered tart pan.
Fill the tart with the following preparation:in a saucepan, gently boil the brown sugar and cream for 10 minutes. Add the chopped walnuts and allow the mixture to cool.
Bake in medium oven. Cooking:40 minutes (th. 5/6 – 210°C)
Unmold and let cool.
Source:Top 100 Desserts. Larousse.