1Short dough: Cream butter and sugar, beat in salt then egg yolks, one at a time. Work flour in, wrap and chill 30 minutes.
2To make filling: Cream butter and beat in almond paste gradually. Add eggs, then beat until very smooth. Stir in lemon zest and flour.
3Preheat oven to 325 degrees F (165 degrees C). Butter the top and sides of an 8 inch springform pan.
4Roll chilled dough into a circle 11 or 12 inches in diameter. Press the pastry into the bottom and up the sides of the pan without stretching the dough. Trim any excess extending above top of pan. Pour filling into dough and spread evenly.
5Bake at 325 degrees F (165 degrees C) for 45 to 50 minutes. Cool 15 minutes in pan then remove sides of pan. Cool to room temperature and sprinkle with confectioners sugar before serving.