Put flour and butter into small bowl and mix until crumbly. Stir in pecans. Press into lightly greased 9x13 pan. Bake for 15 minutes in preheated oven, then set aside to cool.
Beat together cream cheese and 1 cup icing sugar. Spread over cooled shortbread crust.
Beat together pudding mix and milk until thickened (about 3 minutes). Pour over cream cheese layer and chill until firm.
Beat together cream, vanilla and 2 tbsp icing sugar until thickened. Spread over pudding layer and top with slivered almonds.