It was her mother's recipe

It was her mother's recipe, lauded far and wide among family and friends, talked about at dinner parties, denied to others when asked. When it was time to pass the treasured recipe down there was much fanfare, the secret finally endowed to the precious chosen with obliged anticipation, the proper reverence. Yet when presented, this scrappy thing from decades prior... it revealed itself to be clearly cut from a plastic bag of Tollhouse chocolate chips. So much for proprietary.

And when her secret was discovered, there was only one thing left to do: recopy the recipe into a faded notebook, burn the evidence, and start baking legendary pies.