"This is so easy to make up, and very chocolaty. It's one of my favorite low-carb desserts. It could probably be cooked on top of the stove, if you prefer, but doing it in the microwave is fast and easy. My carb-eating family cannot tell this is a low-carb dessert! Suitable for: gluten-free, Atkins®, keto, LCHF, low-carb, diabetic, and low-glycemic diets. Store, covered, in refrigerator. May be frozen and defrosted on the counter with no separation of the pudding."
Whisk confectioners' sweetener, cocoa powder, glucomannon, and salt together in a large microwave-safe bowl or measuring cup; pudding will bubble up during cooking.
Combine cream, water, and vanilla extract in a separate bowl. Whisk gradually into the cocoa mixture until no dry spots remain. Add chocolate pieces.
Microwave the pudding on high for 1 minute. Whisk briskly and continue cooking, whisking every 40 seconds, until bubbling and chocolate is melted, about 3 minutes. Pour into seven 4-ounce ramekins or serving dishes. Cover with plastic wrap and refrigerate until thoroughly chilled, at least 30 minutes.