I have a coffee cake recipe that I have been making for about 4 years. Recently when I am making it the cake is breaking into thre pieces. While it is baking , I see it cracking on the top. So I have purchased new baking powder and soda, fresh butter and cake flour. My eggs are room temp before I add them to my butter and sugar. When I add my dry goods I mix it for 90 secs. I am stumped as to what could be causing the cakes to crack. Any suggestions? Dori P.S. I cool it for 15 mins before I take it out of the pan to completely cool.