Use vegetable spray to butter 5 round layer cake pans (8-inch pans) and dust with flour, remove excess.
Cream the butter with the sugar until light. Add the egg and beat well. Stir in the extract, salt, and almonds. Add the flour and mix thoroughly. Divide the dough into 5 equal parts. Put in the refrigerator for 1 hour.
Roll each of them between 2 sheets of waxed or parchment paper to fit the pan, or pat the dough evenly into the pans gently. Bake in a moderate oven 325 to 350°F for 20 minutes, or until delicately browned. Reduce temperature if it starts to get too brown. Remove from the pans while still hot. Cool. Prepare the filling.
FOR THE FILLING: Cook the prunes in water just to cover until they plump up. Take prunes out of the liquid, pit them and grind them.
Bring to the boiling point the ground prunes with the 1 cup sugar, cinnamon, lemon juice and prune liquid. Put the layers together with the warm filling. Let the torte stand for about a day (24 hours) before cutting it. Serve in slices.