It uses both baking powder and baking soda. If you don't have baking powder, increase the baking soda to 2 1/2 teaspoons.
Since this is flavored with unsweetened cocoa powder, the recipe uses either boiling hot water or hot coffee to help the flavor of the cocoa to bloom and give the cake a richer chocolate flavor.
Could not find 18.5 cake mix. took advice from other comments. Added 5 TBSP flour, 2 TBSP sugar, 1/2 tsp baking powder and pinch of soda.
bake 35-39 minutes.
You can make the dough ahead of time, refrigerate it, and let it rise at room temperature until doubled in size, about 1 1/2 hours. Or you can make the rolls, let them cool, and freeze them in Ziploc freezer bags.