I guess she wanted to cook for you something special, buy her some flowers and ask forgiveness and tell her you love her, she will forgive you and she will understand you.
I think she feels bad about you interrupting her serious work. It's like when we do stuff we really like. We don't want to make a mistake and mess it up. So I can understand how frustrated she must feel when someone else does it for her.It's best you give her some time to think. But let her know in humble ways that you're really sorry. Sometimes explaining stuff can come across as you hurriedly trying to fix the problem. She wants you to know that you really hurt her feelings. And that's okay.Stuff like this will pass in time. But you have to find ways to show that you care about what you did. Say sorry every now and then. Not too much or too often. And when you do apologize, always be sincere, succinct, and polite. Never drag it out to another explanation.And if she does ask you why you did it, calmly explain how you felt inclined to help her. And that you recognize that your good intention doesn't make up for what you did to her hard work.
I think this is just a cute argument, and your girlfriend just wants you attention. Girls really like to play, they want to be chased by their boyfriend. A simple sorry and treat her to eat outside will help you a lot. But honestly, try to ignore her after so many rejected apologize, I know she will initiate to talk to you.