Preheat oven to 180 degrees C. Grease and flour a ring tin.
Sift the flour and spices together into a bowl. In another mixing bowl, beat the white and brown sugar, vegetable oil, butter, apple sauce, vanilla, pumpkin and eggs together until smooth. Gradually beat the flour mixture into the pumpkin mixture, 1/2 cup at a time, until completely smooth and well blended. Pour the batter into the prepared ring tin.
Bake in preheated oven until a skewer tests clean, about 1 hour. If not quite done, place a sheet of aluminium foil over the top of the pan and bake 10 minutes more. Cool the cake in the pan 30 minutes before inverting onto a serving plate. Cool completely before glazing.
To make the glaze, mix the cream cheese with the butter, icing sugar, rum essence and milk in a bowl. Heat in a microwave oven for 15 seconds. Drizzle spoonfuls over the cooled cake. Refrigerate until ready to serve.