Brownie problem
 

Have used same recipe for 30 years, using Hershey chocolate syrup. The last two times, when baking, a couple of large bubbles are created, I've poked them, and the brownies don't raise much, taste okay. Oven temp is correct, what could be wrong? Thought maybe Hershey changed their recipe for the syrup. Any ideas?

If you use baking powder in this recipe check the date on the can and see it that is the problem.

That's my guess too. I had baking powder that was outdated and as a result had a few baking disasters. I know these food manufacturers do change their recipes from time to time also. Good luck!