The phrase "hard crack phase" makes me think of...
a. 1991 through 1993, then rehab
b. my time in Catholic school
d. two or more of the above
According to my sister, "hard crack phase" is a candy-making term used to describe somewhere around 300 degrees. Certs me. I was just looking everywhere in this city for "toffee bits" in order to make a blondie recipe from the October 2003 Everyday Food, which Martha promised were "easy to find near the chocolate chips in any grocery store," with little success (Although my sister also says they are in fact easy to find near the chocolate chips. Ha! Maybe in Indiana!). So I decided to make my own toffee. You would not believe how easy it is! I made one batch plain to break up into bits, and one batch of chocolate-almond toffee bark. The whole process took about 10 minutes. Here's how:
1 cup butter
1 cup sugar
chocolate chips (I prefer semi-sweet, but some like milk)
Heat the sugar and butter in a saucepan over medium low heat, stirring slowly but steadily. You will see the mixture go through several phases, sort of like a chemistry experiment. When it turns beige, after 7-8 minutes, throw in a few almonds, give it a stir to mix. Don't let the color get too dark - if it starts to accumulate little bubbles on the surface, it's overdone and will taste burned. I had to experiment with a smaller batch to figure out when it was done, but I'd say 7-8 minutes should do it on a gas stove at least. Remove from heat and pour the mixture out onto a greased cookie sheet or pyrex. Sprinkle chocolate chips over the top. Let them melt and spread them out with a spatula, then sprinkle with more slivered almonds. Let cool, then crack up into 2" pieces. Yum!
If you must do it the high-maintenance way, here's Martha's toffee recipe from the Food Network.