Pulse together flour, 1/4 cup sugar and salt in bowl of food processor fitted with metal blade. Pulse in butter until crumbly. Stir egg yolks and vanilla together and pulse into flour mixture. Remove from processor and work with hands to make soft dough. Roll dough out between 2 sheets of waxed paper to about 1/8-inch thickness. Remove waxed paper and place into 9-inch tart pan, pressing dough firmly into sides. Place in freezer for 30 minutes.
Preheat oven to 375 degrees Fahrenheit Toast almonds in shallow pan for 7 to 9 minutes or until brown. Remove and let cool. Finely chop in food processor with metal blade. Set aside. Remove the crust from the freezer. Line crust with aluminum foil and top with pie weights or dried beans. Bake for 15 minutes. Remove weights and foil and let cool.
Beat egg yolks and 1/2 cup sugar together on medium speed in large bowl until pale. Stir in lemon juice and zest, then melted butter, almonds and almond extract. Place tart pan with crust in shallow baking pan. Carefully pour filling into crust. Bake for 20 minutes or until tart is set and a rich brown color. When ready to serve dust with powdered sugar.
Recipe courtesy of Calhoun Cooking School, Min, MN