King Arthur Flour Unbleached Cake Flour Blend in Pastry & Baking Posted January 27, 2011 I just used some recently. I'm not sure if it was the flour, but the crumb in the cake I made was definitely different. As if there was a little more protein content? I had to make the cake twice. First time was a bust and I blamed myself. The second time, the cake came out acceptable, but there was some tunneling and stuff that I don't normally get with this particular cake. A little tougher, too.