I got called in to my boss's room for this email

ok so me and some of my colleagues got promoted a while back. To celebrate that, we decided to buy some cakes for everyone in our department.

When the cakes were ready, I sent out the following email to invite them to get those cakes in the pantry:

Subject: Have Some Cake

Dear all

As our thank you, we got some cakes for you in the pantry.

Pleae come on out and take a break, have some cake!

Cheers

Then I got called in by my boss whos is from Hong Kong and blamed for bad grammars. He said some "cake" are with an s some "cake" without. But I said "cake" can be either countable and uncountable depending on what im trying to say. He also said "as a thank you" and "come on out" is Hong Kong styled English. He said he was ashamed of my bad English.

What do you guys think? I know it's a bit informal but come on this is just some sort of casual internal communication within the department.