Method:

1. Combine flour, sugar, and baking powder in processor and mix. Add butter in bits and process a few times. Mix egg yolks, sour cream, and lemon zest, and add. Process just until dough forms. Press into a ball, then divide into 2 parts, one twice the size of the other. Chill in plastic wrap for at least 2 hours before rolling out.

2. Butter the bottom and sides of a tart form. Roll out the larger piece of dough about V4 inch thick and line pan, trimming edges with pastry cutter or sharp knife. Refrigerate. Roll out remaining dough to V4 inch thickness and cut into V2 inch strips the width of the pan. Refrigerate. 

Filling:

1. Plump raisins in hot water and drain. Mix cheese and egg yolks. Add vanilla, lemon juice and zest, and raisins. 

2. Beat egg whites with sugar until stiff and fold in. Fill the prepared pastry, spreading evenly. Arrange pastry strips on top, weaving them for a fancy effect. Crimp ends and edges together. 

3. Bake in preheated 175°C oven until done, about 45 minutes. 

4. Brush with egg white glaze and sprinkle with coarse sugar. Bake 5 minutes more until top is golden. 

Serve at room temperature.