I cann't get past December in Cake Mania 1

Helpie!!!

I like Cake Mania 1, but how can I get past December????
I play all the month's till December!!!!
December is a big problem for me, can anybody help me????
What can I buy the best through all the month's ???
Who can help me???

Thanks from Irene from Gouda, the Netherlands a very big fish gamer!!!!