I made a pratice sheet cake this weekend and it was a mini disaster. I used a 9*13 brownie pan and buttered and flour it really well. which always works. But, the chocolate layer stuck. Then it cracked and then that caused the final layer of icing to be crumby and my star tip broke. It kept piping these weird swirls like something was stuck in the middle. I did rosettes instead. Decent looking cake in the end. But a lot of work. My question is anyway to get the star tip not to do that? Also how can I keep my cakes from cracking. Finally can I use the 1M swirl or 2D tip to make 'roses for the top' of the cake and pipe leaves around them. I can't make buttercream roses. Thanks so much!!
Sorry this happened to you! I am not sure is this helps, but I sometimes have to check my star tips and make sure the points have not been pushed inward. A few times I have had to readjust them carefully by pulling them out slightly. .
As for your chocolate cake sticking, I no longer use butter to grease a cake pan. Parchment paper is my best friend! However, if I am using a pan that is odd shaped, like a star, I only use shortening and flour.