Cream butter and sugar together until smooth. Add egg yolks and blend.
Stir in flour and salt and mix just until dough comes together. Turn out onto a lightly floured surface and knead 1 minute.
Shape dough into a disc, wrap and chill for at least an hour. If making dough far in advance, pull dough from refrigerator an hour before rolling.
Preheat oven to 375 F.
On a lightly floured surface, knead dough again for 1 minute. Roll out pastry to 1/4 –inch thick.
Line a 10-inch removable-bottom tart pan with the dough, trim rough edges and chill for 30 minutes.
Prick crust bottom with a fork and bake for 15-20 minutes, until edges are lightly browned and centre of shell is dry. Allow to cool before filling.
Reduce oven temperature to 325 F and place tart shell on a baking sheet.
Whisk together lemon juice, sugar, eggs, cream and zest and pour into tart shell.
Carefully move tart to oven and bake for 25-30 minutes, until tart stops jiggling when you tap it. Tart filling should not soufflé at all. Allow tart to cool at room temperature for a bit, then chill for 2 hours before finishing.
Arrange raspberries on top of tart – starting at the outside edge and moving in works best.
Dust lightly with icing sugar, if you wish, and serve.
Tart with lemon filling can be made a day ahead and finished with raspberries up to 6 hours before serving.