I’ve only had with cream cheese ‘frosting’, but it is clearly a variation of a savory cake.

https://www.inthekitchenwithelisa.com/scandinavian-sandwich-cake

To answer your question, no it is not valid. The fact that you don’t actually stand by the word offended really answers yourself.

Why choose “offended” as the verb here? I’m not saying I’ve never seeing an offensive movie… But what you described is an annoyance at most.

It’s almost as if you are claiming offense to be contrarian.