Preheat oven to 375. Spread nuts evenly on the bottom of the 9 inch unbaked pie shell; set aside. In mixing bowl, mix melted butter, vanilla, and flour. Add salt. Add eggs and beat til thoroughly mixed. Add maple syrup, and skim milk. Mix well. Pour the filling over the walnuts in the unbaked pie shell. The nuts will float to the top, use a spatula to gently push them under the liquid. (Making sure they are well saturated with the mix will keep them from burning)
Bake for 50 to 60 minutes, until a knife inserted in the center comes out clean. Allow to cool for 15 minutes before slicing. May be served with whipped cream. (note-Place in oven with care. I let the mix spill up onto the pie crust edge as I put in the oven. These spots of crust burned -- see picture).