DOUGH:

1/2 lb. sweet butter
2 c. flour
3 egg yolks

FILLING:

2 c. milk
3 egg yolks
1/2 c. sugar
3 tbsp. flour
1 tsp. vanilla

Add sweet butter to one cup flour; cut in as for pie dough; set in refrigerator. Mix egg yolks with second cup of flour; add a few drops of water to make stiff dough. Roll out dough. Spread the cold butter-flour mixture over egg yolk dough. Fold in four layers; set in refrigerator for 20 minutes. Roll to about 1/4 inch thickness; fold four times again. Repeat this process four times. Roll out to fit pan 12 x 15 inches. Fold dough in envelope fashion. The more folding is done, the flakier it will be. Bake at 425 degrees until light brown. For filling combine milk, sugar and flour; cook until thickened. Remove from heat; add egg yolks and vanilla.