Cream butter, sugar, and salt in mixing bowl until light and fluffy.
Add pumpkin and spice and mix completely.
Add eggs one at a time beating well after each addition.
Add milk alternately with flour, mixing well after each addition; do not overbeat.
Stir in vanilla.
Pour into two greased and floured 8x4 inch loaf pans.
Bake at 325 degrees F for approximately 1 hour and 20 minutes. Test for doneness with a wooden skewer or toothpick.
Cool for 15 minutes and remove from pans. Cool completely on a wire rack.