Place chocolate in a heatproof bowl and microwave at 30 second intervals, stirring between each interval until chocolate is melted. Set aside to cool for 10ish minutes.
If using a stand mixer, fit with paddle attachment.
In a large bowl, beat together cream cheese and butter until smooth.
Pour in the white chocolate, and beat until smooth. Add in lemon juice and beat to combine. With a large spoon or rubber spatula, fold in the chocolate sandwich cookies until they are fairly uniformly distributed (like chocolate chips in cookie dough).
Spread frosting on cupcakes.
Notes
*A note on white chocolate: look for a white chocolate that has cocoa butter listed as one of the ingredients. There are a lot of things that seem like white chocolate, but without the cocoa butter, they are not real white chocolate. There is a difference in taste.Adapted from The Cake Bible