Place cookies in food processor. Whirl until finely crumbed; you should have about 2 cups of cookie crumbs. Add butter and sugar. Whirl until combined. Scrape into 9-inch tart pan with removable bottom, pressing evenly over bottom and up sides. Refrigerate until firm.
Stir together eggs, egg yolks, sugar and lemon juice in heavy-bottomed saucepan. Place over low heat; cook 6 to 10 minutes, stirring constantly until thickened and just beginning to simmer; do not let boil. Do not over stir or stir too vigorously, or mixture will separate. Place pan in large bowl of cold water. Stir in butter until blended. Cover with waxed paper. Let cool 45 minutes.
Pour filling into tart shell. Refrigerate to chill thoroughly.
Spoon whipped cream into pastry bag fitted with star tip. Pipe cream onto tart. Arrange fruit on top. Garnish with fresh mint sprigs if desired. Makes 12 servings.