This is the second time I have made this to my DH's delight. The first time I messed it up by using the electric mixer. The batter was a stunning purple color but I had a heavy, dense and kind of gummy layer on the bottom. This time I just mixed and added all of the wet ingredients into the dry and gently mixed them by hand just until there was no dry left. I don't have a 9x9 pan so it was scraped into an 8x8 and it was just perfect at 30 mins. I should mention that I used Splenda for the sugar. We just love this cake, it's not overly sweet (which is good), moist, light and simply delicious!