Place pecans in bowl of a food processor and process until fine.Set aside.Peel,core and quarter apples and place them in bowl of processor and pulse until they are in medium-coarse shards or about the size of almonds.Set aside.
Place butter in large mixer bowl,add sugar and beat until fluffy.Add egg and beat until blended.Add soda,salt,cinnamon,nutmeg,and mix quickly.Add flour and beat until just blended.Stir in apples and nuts.
Pour mixture into a greased 9 inch round pan and bake for 30 minutes or until top springs back when touched with finger.Cool slightly.Center may sink somewhat.
For caramel sauce,melt butter,brown sugar and salt in a small saucepan over medium heat.Bring to a boil,stirring with a whisk.Remove from heat and whisk in vanilla and milk.
Cut cake into 8 wedges.Ladle a large spoonful of sauce on the bottom of eight desert plates.Place a wedge of cake on top of sauce.