An internet search returns the fact that brittle means easily broken, cracked, or snapped. MY version of cinnamon brittle was more about breaking a tooth. Cooked to 340 degrees as instructed, this was very, very hard. However, if allowed to melt in your mouth for a moment, it became cinnamon goodness.
The recipe can be found in Charity Ferreira’s, “Brittles, Barks, & Bonbons” on page 31.
long before the mixture reached 340 degrees:
cinnamon for flavor:
sugar mixture cooked to a ‘spatula spike’