Mix flour, brown sugar, butter, and nuts until crumbly. Spread on foil-lined baking sheet. Bake at 350 degrees 10 minutes or until golden. Cool. Break apart into crumbs. Line a 9-x5-inch loaf pan or metal ice cube tray with foil, leaving 1-1/2 inch collar around edges. Sprinkle 2/3 of the crumb mixture in bottom. Beat egg yolks until thick and lemon colored. Blend in sweetened condensed milk. Add lemon peel and lemon juice; stir until thickened. Beat egg whites until foamy. Gradually add sugar into egg whites and continue beating until stiff peaks form. Fold into lemon mixture. Pour mixture into prepared pan. Sprinkle remaining crumbs on top and freeze until firm. When frozen, lift from pan and slice. Serves 6.
My grandmother used to make a similar dessert. She made her dessert in a metal ice cube tray. Please be aware this recipe has raw eggs.