Line a 9 by 5-inch loaf pan with a piece of parchment paper.
Sift together the ginger, cinnamon, nutmeg, cloves, and black pepper and set aside.
Add the sugar, cream of tartar, salt, and water to a medium saucepan over medium heat. Cook until the sugar caramelizes; it should be a golden amber color. To help the sugar dissolve, you can gently swirl the pan, but don’t stir. If sugar crystalizes along inside the pan, you can use a wet pastry brush to brush it down.
Once the sugar is amber-colored, turn off the heat and stir in the butter.
When the butter is melted in, stir in the cream, molasses, and spices until combined.
Carefully pour the caramel into the prepared pan and let it cool to room temperature before cutting (at least 4 hours, but overnight is best).
Carefully cut the caramel into 20 pieces with an oiled knife, wrap each in parchment paper, and store in an airtight container at room temperature for up to 1 month.