Under measurement of liquid.
Use the proper amount of liquid. When possible, use a scale to weigh the liquid.
Oven temperature too low.
Have oven temperature checked for accuracy, follow package directions for proper temperature.
Too much floor time.
Limit floor time of scaled batter to no more than ½ hour.
Under baking.
Follow package directions for optimum quality.
Hand mixing.
Over mixing of batter.
Air velocity too high in convection oven.
Regulate baffles for controlled air flow.
Under measurement of liquid
Use the proper amount of liquid. When possible, use scale to weigh liquid.
Over mixing of batter
Follow package directions for optimum quality
Have oven temperature checked for accuracy.