How to convert Task<list> to task<long>

while executing below code getting conversion error :how to covert from task to task 

public class EmployeeData
    {
        public static async Task> GetEmployee()
        {
            List EmployeeData = new List()
            { 
              new EmployeeData()
              {
               
                    Id = 1,
                    Name="Abc"

                }
            };
            return  EmployeeData;