Original: Wakefield is said to have been making chocolate cookies and on running out of regular baker's chocolate, substituted broken pieces of semi-sweet chocolate from NestlÃ thinking that it would melt and mix into the batter.
Simplified: According to the saying, Wakefield was making chocolate cookies and because there was no more regular chocolate, she used broken pieces of semi-sweet chocolate instead, thinking it would melt and mix into the batter.