To make dough: in a small bowl, combine 1 cup flour, 1/2 cup ground almonds, and 1/4 cup sugar; cut in butter until crumbly. Add extract. Shape dough into a ball, gently press dough against the bottom and up the sides of a 9-inch springform or cake pan. Refrigerate for 30 minutes.
To make filling: in a medium-sized mixing bowl, beat cream cheese, 1/4 cup sugar, and cream of tartar until smooth. Add egg; beat on low just until combined. Pour over crust.
To make topping: in another medium-sized bowl, combine brown sugar, 1 tablespoon flour, and cinnamon. Add apples and stir until coated. Spoon over the filling. Sprinkle with 1/3 cup slivered almonds.
Bake at 350 degrees F (175 degrees C) for 40-45 minutes or until golden brown. Cool on a wire rack for 10 minutes. Carefully run a knife around edge of pan to loosen; cool 1 hour longer. Refrigerate overnight. Remove from pan.