Bring to a rolling boil – takes a while and will burn very easily. Don’t rush. Once the butter/sugar mix is boiling, boil for 12 minutes – no longer.
Pour hot butter/sugar mix over prepared pan and immediately cover with the rest of the grated chocolate bar, then the rest of the nuts. Press lightly into the hot sugar mixture.
Let cool completely. When cool, use a butter knife to break the candy up. The pieces will be irregular.
Note: my mom also used walnuts and pecans when she had them.