NOTE: Make the puree by peeling and pitting 6 to -10ºC resh peaches and blending them to a puree in a blender. Cream the sugar and shortening together, then add the eggs and blend well. Add the peach puree and the dry ingredients. Mix well. Add the vanilla and chopped nut, if used, stirring until well blended. Spoon into muffin tins that have been sprayed with a non-stick coating. Bake at 160ºC . for 25 to 30 minutes or until done. Let cool in the tins for a few minutes before removing them to a rack to cool.