Beat butter, egg and sugar in small bowl until combined, 2 minutes. Beat in extracts.
Sift flour, baking powder and salt into medium-size bowl. Beat flour into egg mixture until dough forms.
Roll dough out between 2 sheets of waxed paper into 10-inch circle. Remove top sheet. Invert dough into 9-inch springform pan; press over bottom and 1/2 inch up sides of pan. Peel off paper. To patch any small holes, push dough together with fingers.
Scatter nuts over crust; lightly press nuts into crust. Brush pastry with a small amount of egg white. Discard rest of white. Wrap bottom and sides of 9-inch springform pan with foil.
Heat oven to 325 degrees F.
Beat together ricotta cheese, sugar, eggs, flour, vanilla and lemon rind in medium-size bowl until well combined, about 2 minutes. Pour into crust. Place springform pan in large baking pan on oven rack. Pour hot water into large pan to come halfway up sides of springform.
Bake in 325 degree F oven for 1-1/4 hours or until filling is set. If top of filling begins to brown too much, cover loosely with aluminum foil. Remove springform pan from water bath; carefully remove foil from pan. Run knife around edge of cake. Cool pan on wire rack. Refrigerate 6 hours or overnight.
Remove side of pan. Melt jam in small saucepan. Brush around top edge of cake, about 1 inch. Sprinkle border with nuts. Makes 16 servings.