This recipe is about as close as I can find online to compare with the ones my Mom always made for holidays. 

https://savvyhomebody.com/candied-sweet-potatoes/#comment-36881

She did not make them into "pennies" however, she boiled whole sweet potatoes in the jackets, let them cool a bit, peeled them and sliced them lengthwise and placed them in a 9 x 12 pan, then sprinkled or poured the rest of the stuff on top.  I do remember hers had a rather floury type crumble crust on top that contained the cinnamon and ginger and cloves, etc. and was kinda sorta crunchy.

I'm digging through recipes trying to decide what to take to my son's house for upcoming holidays.  The kids always request my baked beans with hamburger, and the sweet potato casserole.  I am also taking a ribbon jello salad (you know what I mean, 2 layers of different flavored jello with a middle layer made of thick heavy whipping cream mixed with spices and crushed pineapple and mayo made into a creamy layer to go between the 2 layers of jello).  I like to use red and green jello for Christmas and orange and lemon yellow for thanksgiving.  I think there is already a recipe here for my ribbon salad recipe, you'd have to do a search using the bar at the top of the page.