Too much lemon zest in cake.. want to fox

What about using the lemon cake as a base for an English Trifle? Adding in a custard, fruit and possible some sweet liquor would go a long way to cutting down or masking the overpowering lemon taste. A brief web search should bring up dozens of inspirational recipes like these: https://www.delish.com/holiday-recipes/christmas/g3090/trifle-recipes/

If you added the zest after baking, and you are asking us, presumably you can just scrape it off.

A similar question was answered on quora with suggestions of serving with whipped cream or vanilla ice cream.

Another suggestion - top with chocolate ganache or buttercream, hoping that both the chocolate and sugar will balance the lemon zest bitterness.

However, if the zest is imbedded in the cake and taste is very strong, it may not be fixable. So try any solution on a single serving. If it works, proceed.