YOU SAID:

if i had known you were coming, i would have baked a cake

INTO JAPANESE

私はあなたが来ていたことを知っていたら、私はケーキを焼いただろう

BACK INTO ENGLISH

If I knew that you were coming, I would have baked the cake

INTO JAPANESE

私はあなたが来ていることを知っていたら、私はケーキを焼いたでしょう

BACK INTO ENGLISH

If I knew that you were coming, I would have baked the cake