Google knows nothing about lassy mogs. Hopefully this entry will fix that.
In an earlier era in Atlantic Canada, the “lassy mog” was a classic home-baked treat. Its charming name is derived from the local dialect for the region’s widely used sweetener, molasses (“lassy”) and a small, low-rising cake (“mog”).
So there you go. I’m surprised I didn’t hear anything about them when I lived in Newfoundland, but they’re pretty good cookies.
Update: Recipe found. See below.