Hi ML- The details of everything that is happening is quite complex and not dependent on any singular factor in the recipe. The important thing to note is that the general act of over-mixing, particularly at high speeds, whether at the creaming or flour addition stage, will cause interactions between ingredients that lead ultimately to a breakdown of the proper structure of the cake, which is what you spent so much effort developing before we beat it back down. So just stick to slightly lower speeds and watch your batter to be sure you stop it as soon as it is fully incorporated and fluffy and you should be all set to go with a beautifully-crumbed cake. If you have any more questions, please feel free to contact our Baker's Hotline at 1-855-371-2253. Happy Baking! Jocelyn@KAF

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