Chocolate Soufflé

This is my Granny Alice's recipe. She used to love to make puddings, especially ones cooked in a water bath. It's the perfect comfort food, and just the thing when you need some of your Granny's loving.
1/3 c seed pearl tapioca
1/2 c sugar 
1/4 tsp salt 
1/4 c unsweetened Dutch cocoa 
2 c milk 
2 Tsp butter, unsalted 
3 egg yolks, well-beaten 
3 egg whites, whisked

Preheat oven to 350°F.
Boil the tapioca, sugar, salt, cocoa and milk for about 10 minutes or
so, stirring constantly. 
Stir in the butter and allow the mixture to cool slightly. 
Add the egg yolks, and stir well, and then fold in the egg whites.
Carefully pour the chocolate mixture into a buttered casserole dish,
and place in a water bath.
Bake for about 50 to 60 minutes.