In a large saucepan over medium heat, add half & half, sugar, vanilla seeds, vanilla pod, salt, cloves, and allspice.

Heat until wisps of steam rise and very small bubbles begin to form at the edge (do not let it simmer).

In the meantime, add egg yolks, pumpkin, cinnamon, and nutmeg to a mixing bowl.

Whisk to combine.

When half & half mixture comes to temperature, very slowly whisk into egg mixture.

Be careful not to add too much at once or it will curdle the eggs. (when in doubt, add a ladle at a time and whisk continuously until incorporated).

Return mixture to saucepan and place over medium heat, stirring constantly until mixture coats the back of a wooden spoon (about 170 degrees on an instant read thermometer).

Strain mixture through a sieve into mixing bowl.

Bring to room temperature, cover in plastic wrap, then chill in refrigerator 4-6 hours (or overnight)

Freeze according to your manufacturer's directions for your ice cream maker.

During the last 2 or 3 minutes of churning, add chopped chocolate and continue until mixed thoroughly.

If you desire a firm texture, place ice cream into the freezer for 3 or 4 hours.