In a large saucepan, over medium heat, melt the butter. Stir in the sugars, cane syrup and spices, stirring until the sugar dissolves. Add the apples and salt. Mix well. Cook for 20 minutes, stirring occasionally. Dissolve the cornstarch in the water. Stir the mixture into the apples and continue to cook for 10 minutes. Remove from the heat and cool completely. In a food processor or blender, puree the mixture until slightly smooth.