How do I get my blondies to not turn out cakey?

There are a couple reasons your blondies can turn out cakey. If you use different ingredients than the ones listed or over-baking your blondies. Be sure to take the blondies out when a toothpick comes out mostly clean! That will help keep the gooey, blondie texture!

Can I freeze these blondies?

Let blondies cool to room temperature and then cut into bars. Wrap the bars individually in parchment paper, wax paper, or aluminum foil. Then, store in a Ziploc bag. To prevent freezer burn, make sure to remove as much air as possible. If stored properly, bars will stay fresh for 6 months. Frost after you defrost and are ready to eat.

Can I use a different kind of protein powder?

If you want to use another type of protein powder, just make sure it is also a whey + casein blend. An all whey protein powder will cause these blondies to turn out more cakey. Not all protein powders respond the same when baked, so just make sure you use one you know bakes well.