How do I get the flaky top on ooey gooey butter bars? I'm making Paula Deen's Ooey Gooey Butter Bars (also known as Ooey Gooey Butter Cake) for holiday goodie baskets. I'm having trouble getting the top to be flaky like it is on the bars sold at the store - the same kind of flaky top that's on brownies.

I'm guessing I'm either not mixing something long enough or mixing it too long or something. I've seen pictures of the process online and my top batter looks EXACTLY like the batter in the picture, but something is going wrong. In my eight tries, it's only turned out right twice. I can tell when it's going wrong during the baking process, because the top fluffs up and the crust never forms.

For the unfamiliar, this is a bar with a cake mix-butter-one egg crust on the bottom. The topping is a block of softened cream cheese, one stick of melted butter, two eggs, vanilla and two cups of powdered sugar. 

Could it be the quality of the ingredients? I've used no-name butter sometimes and other times Land O'Lakes. Help!
With the recipe you mentioned there is no indication as to what temperature the cream cheese and butter should be at and I'm guessing that's one possible item making the difference.  Since it looks a little like a creaming or foaming (sponge) method for whipping ingredients, I'd try to make sure my butter, eggs, and cream cheese, but especially butter, were around 70 degrees F.  You want them to be able to incorporate air.  The first link talks about how to get things crispier or fluffier based on how long you cream, etc.  Then you will want to play around with batter temperature when it hits the oven.  

Also note that more fat in a cookie recipe, at least, is equivalent to crispier.  Are you subbing nuefchatel cheese or low fat or no fat cream cheese for the cream cheese?  If so, don't.  Moisture in sugar has an impact so make sure you aren't subbing any other sugar for powdered.

Real gooey butter cake is a yeast cake rather than the rip-off versions that use cake mix and not really all that much more complicated, although more time consuming.  You may want to try doing a more authentic recipe, or at least one that uses a yeast cake.  I have had success with the one linked.