Yes man, whatever she does even if it upsets you its out of your control, however for the future times just plan ahead, hey the birthday its so....could you bake the cake? If she says no, then you bake the cake...not a big drama, but don't judge her for doing things, imagine today you were the one going out with your friends and she say to you what you say to her....you wouldn't like it right? Most of the time when you feel in a place like that all you have to do man its remember this that I am going to tell you now:

1 reverence for all of life: that means respect even if you dont agree
2 sincerity which its honesty
3 Gentleness: its a manifest of kindness
4 Suportiveness: which is service to others

Only for today: instead of doing all for me I will do things for others out of service..
In the cake case instead of thinking ahit she is going out bla bla bla, think nice I will always remember this moment baking the cake for my little one, I will make sure I prepare it with love because I am doing a service for my little one at the end of the day...and nothing else will interfere at that time while I am baking...

When the student its ready, the teacher will appear...
Even after all this time the sun never says to the Earth, "You owe me."
Look what happens with a love like that,It lights the whole sky.