1. Place the cream, milk, 1/2 cup of the sugar, unsweetened coco powder, vanilla extract, and earl grey tea bags into a large saucepan. Heat slowly for 10-15 minutes, keeping it just under a simmer.
2. Meanwhile, place the egg yolks, 1/2 cup of the sugar, and pinch of salt in a bowl. Whisk until the egg yolks have thickened and are slightly lighter in color.
3. Remove the tea bags from the milk mixture. Whisk 1/3 cup of the hot milk mixture into the egg mixture to temper it. Then, slowly whisk the egg mixture into the milk mixture. Stir custard until thickened and coats the back of a spoon.
4. Immediately pour custard into a bowl set in an ice water bath. Stir occasionally until cooled. Refrigerate until very cold, or overnight. Freeze in an ice cream machine and place in a covered container in the freezer.