1. Cook the pumpkin in plenty of water until it gets soft.
2. Process the pumpkin, egg, oats, erythritol, baking powder, and vanilla essence once it's soft.
3. Melt the chocolate in a different bowl. You can either do it in a double boiler or in 10-second intervals in the microwave.
4. Mix the chocolate into the mixture of pumpkins.
5. Blend thoroughly and transfer the blend into a mold (previously greased).
6. Bake at 180ºC/350ºF for 25 minutes.