Hi everyone. I have seen a number of chocolate cake recipes that make use of hot/boiling water. Has anyone come across a non-chocolate cake recipe that also uses hot water?

AThe hot water is for bringing out the flavor of the chocolate. If there is no chocolate there is no need for it. If fact, your ingredients should her room tempurture. Generally, you heat the water, add the cocoa, mix and let sit. You don't add it to the flour mixture hot, you wait for it to cool.

Most of the recipes I have seen advises to add the hot water in a stream and not to allow it to cool. I understand that the hot water blooms the cocoa powder, but is there any other effect, particularly on the flour? The reason I'm asking is that many recipes that call for hot water seem to produce a moist cake. So I'm wondering if the hot water has some effect on the flour that causes this result.

In bread baking, there is a method called "water roux" which calls for a portion of the flour to be cooked with water to form a loose paste, and this is added to the dough, and results in a bread with more moisture. I wonder if a similar effect is achieved when adding hot water to cake batter.

Yeah I have seen that method for bread, particularly in Japanese bread recipes.  I don't think it's the same with cake batter because you are not developing any gluten the way you are with the roux (cooking it over the heat like that).  You basically mix it and then put it in the oven.  The point is to bloom the chocolate and release the flavor.