Preheat the oven to 375°. Grease 1.5 quart casserole dish with butter or coconut oil and set aside.
Bring a large pot of water to boil over high heat. Add the peeled and diced sweet potatoes and cook until tender, about 20 minutes.
While sweet potatoes are cooking, prepare the topping mixture. In a medium bowl, add chopped pecans, almond flour, coconut sugar, cold butter, and a pinch of salt. Mix until the mixture is crumbly and combined. Set aside.
Once cooked, drain the sweet potatoes and return to the bot. Mash the potatoes using a masher or potato ricer until smooth.
Add the almond milk, coconut sugar, melted butter, eggs, Collagen Peptides, cinnamon, and salt. Mix well until combined.
Transfer the sweet potato mixture into the prepared casserole dish, smoothing into an even layer. Sprinkle the prepared pecan topping mixture evenly over the top.
Bake for about 30 minutes until the edges are light brown.
Remove the casserole dish from the oven and let it cool for 10 minutes. Serve warm.
Store leftovers in an airtight container in the fridge for up to 3 days.