Preheat your oven to 400°F (200°C). Scrub the sweet potatoes clean, then poke a few holes in each with a fork. Place them on a baking sheet and bake for 45–50 minutes, until the flesh is tender when pierced with a knife.
While the potatoes roast, cook the bacon until crisp. Let it drain on paper towels, then crumble into small bits.
Dice the apples into small chunks. In a skillet, melt the butter over medium heat. Add the apples and a pinch of salt, sautéing for 4–5 minutes until they start to soften. Stir in the brown sugar and cinnamon, cooking for another minute or two until the mixture is glossy.
Remove the potatoes from the oven. Allow them to cool just enough to handle, then slice a deep opening in the top of each potato and carefully scoop some of the center flesh into a bowl, leaving the skins intact.
Mash the potato flesh with a fork, then fold in the sautéed apples, crumbled bacon, and toasted pecans. Taste and adjust with a pinch more salt if needed.
Return the filling to the potato skins, spooning it evenly. If you like, return the stuffed potatoes to the oven for 5–7 minutes to warm through and meld the flavors.
Serve hot, topped with a dollop of yogurt or sour cream and a sprinkle of fresh parsley.