Bring the ingredients for the filling to room temperature for best results. In a 3-quart pan blend together softened cream cheese, maple syrup, spices, and salt. Add eggs one at a time, mixing briefly after each one. Then blend in pumpkin, milk, and vanilla until smooth. If the cream cheese isn't fully softened, you may see bits of it in the filling. If this happens, warm the filling gently over low heat, stirring occasionally, until the cream cheese dissolves.