"Moje ciasteczka są smaczne."

Translation: My cookies are tasty.

[Sean_Roy]

Yes, they are! I just made some ginger molasses cookies the other day, and they came out super good.

[OrangeKidd1]

That sounds awesome

[miletskiy]

my cakes are tasty ?

[Jellei]

Maaaaaaybe if this was "ciastka" (sometimes a piece of cake that you can buy in a confectionery can be called "ciastko"), but not for "ciasteczka".

[BuchitaBuchys]

Just to be clear, są is "is" for plural, and jest is "is" for singular?

[Jellei]

Well... "is" isn't for plural, isn't it? :) But well, you could say that, I guess.