Pumpkin Bread Pudding with Nutella Glaze

1 cup heavy cream
3/4 cup whole milk
1 cup canned pumpkin
1/2 cup granulated sugar
3 eggs
1 big pinch of salt
1 1/2 teaspoon pumpkin spice mix (homemade recipe here)
6 cups challah or other egg bread (preferably on the stale side) cut into 1-inch cubes
Preparation method