Fill a large pot with water and bring to a boil.
Scrub the potatoes and carefully add to the boiling water. Immediately set a timer for 40 minutes (no need to wait for the water to come back to a boil). When the time is up, carefully remove the sweet potatoes (I use cooking tongs) and let cool. (The sweet potatoes can be prepped up to this point and kept in the fridge for up to 3 days.)
Heat the oven to 350° F.
Trim off the ends of the sweet potatoes and peel off the skin. Slice into ¼" rounds. Lay the rounds in the bottom of a 9x13" baking dish in a single layer. Feel free to cut some of the rounds in half to fit into the edges of the layer, if necessary. Sprinkle with about ¼ teaspoon of salt, ¼ teaspoon of cinnamon and 1 tablespoon of coconut sugar.
Repeat the layering process, overlapping the rounds when possible to cover up gaps (but don't worry about any gaps). Add about ¼ cup of the pecans after the second layer. With the final layer, sprinkle over the last of the salt and cinnamon, about 2 tablespoons of the coconut sugar, and the remaining pecans.
Carefully pour in the apple juice in two or three places around the edge of the dish. Try not to let it splash over the sweet potatoes but don't worry if it does.
Bake the sweet potatoes for 40-45 minutes, until they look a little darker and caramelized. Let cool for 10 minutes, then serve.