Thank you, but sorry I ccould’t be of help. I only had one slice on the first day, so I couldn’t say if the flavor really does fade or how much. I do recall that the flavor of the mousse was very strong in that slice though.

Thanks, anyway, Matthew!  Are you able to describe the flavor?  The matcha tastes more grassy to me than green tea does.  Next time I made buttercream, I’m going to mix some in a sample to taste it, but, if it’s not too long ago and you still remember it, I’d be very interested in what the overall sort of—whatever—is when it’s mixed with cream, sugar, custard, etc.  It’s so hard to imagine it!

I liked all of the components except for the mousse, which was as you said too grassy/mossy for my taste. If I were to make this again, I probably would change the filling somehow—either less matcha, or no matcha with some coloring, or perhaps something like raspberry to get a color contrast.

Thank you so much!!!