According to the LSU AgCenter, part of the answer (not surprisingly) lies in cultural influences. African slaves in the Southern US thought that sweet potatoes were similar to their native African yams. So they referred to sweet potatoes as "nyami."
Louisiana produces a significant share of sweet potatoes in the US. Opelousas, one of LA's oldest cities, hosts the annual Yambilee Festival. Not the Sweet Potato Festival, but Yambilee. Why use the term "yam" when that's not technically what's being grown? Because to LA farmers those orange roots are yams...Louisiana Yams. Also according to the LSU AgCenter, in the 1930s LA farmers wanted to set their sweet potatoes apart from the rest of what was grown in the US. The variety that LA farmers grew back then was a Puerto Rican one and, at the time, was different than what was being grown in the rest of the country. (This isn't the case any longer). These sweet potatoes were sweeter, fluffier, and the flesh more orange. So, they were called yams. Louisiana Yams.
About this time last year, I wrote about my Great-grandma Vick's specialty and family favorite, Sweet Potato Crunch. This year I wanted to share the sweet potato recipe that is my husband's favorite: Praline Yams. It's similar to my great-grandma's since it has a sweet pecan topping and no marshmallows. I really can't stand the marshmallow type of sweet potato casserole. Anyway, I found this recipe many years ago on the back of a can of Sugary Sam's Sweet Potatoes. I changed the recipe a little since no respectable praline would be caught dead with coconut...and we don't like coconut anyway.
I prefer making grandma Vick's sweet potato dish and using "fresh" sweet potatoes...the quotation marks because sweet potatoes are cured for a few weeks after harvesting to up the sweetness. But back to fresh v. canned. Let's face it, Thanksgiving plans usually end up spinning out of control and extra kitchen prep is about as welcome as an alligator to my Thanksgiving backyard turkey fry. Using canned yams definitely saves some time.
Here's the meez: pecans, brown sugar, flour, butter, canned yams. Yep, that's really all there is to it!
Be sure to drain the yams. And look...don't go dirty any extra dishes! Go almost all the way around the can with your can opener and use the lid to help drain away the juices. Trick from mom.
Mix together the pecans, brown sugar, flour, and melted butter to make the topping. Don't worry, it's supposed to be thick.
Since it is so thick and paste-like, I just use my hands. I promise they're clean.
I'm making half a recipe here, since it isn't Thanksgiving yet and I don't need all that food. But, I'm still using a 2 qt dish. When making the full recipe, I use one larger than 2 qt that way almost every sweet potato chunk gets coated in the sweet, nutty topping. But that's just me. I like to play fair with the topping.
Bake for 35-45 minutes at 350.
And here it is, all baked up. The pecans are toasty and the topping is a little bit crunchy and a little bit gooey. And I'm going in.
Ms. EnPlace, adapted from Sugary Sam's Sweet Potatoes
1 40 oz can cut sweet potatoes, drained
1/2 cup chopped pecans
1/2 cup firmly packed brown sugar
1/4 cup flour
1/4 cup butter, melted
Heat oven to 350. Place drained yams in an ungreased 2 qt casserole or baking dish. (Note: I like to spread the yams out even more in a larger dish so that the topping is more evenly distributed) If some pieces are too large, cut them to the size you'd like. In a small bowl, combine remaining ingredients; blend well. Sprinkle over yams. Bake at 350 for 35-45 minutes or until bubbly.