Preheat your oven to 400°F (205°C). Pierce each sweet potato several times with a fork and place directly on the oven rack (set a foil-lined baking sheet on the rack below to catch any drips). Roast for 45–55 minutes, until completely tender when pierced with a knife and the skins are beginning to pull away.

Remove the sweet potatoes from the oven and allow them to cool for 10–15 minutes until safe to handle. Slice them open and scoop the flesh into a large mixing bowl. Discard the skins. Reduce the oven temperature to 375°F (190°C).

Mash the sweet potato flesh with a potato masher or fork until mostly smooth. For an ultra-silky filling, use a hand mixer on low speed for 30 seconds.

Add the Greek yogurt, maple syrup, vanilla extract, cinnamon, nutmeg, ground ginger, and sea salt. Mix until fully combined and smooth. Taste and adjust sweetness with additional maple syrup if desired.

Add the beaten eggs and fold them in until just incorporated — do not over-mix once the eggs are added.

Lightly grease a 9x13-inch baking dish (or equivalent 3-quart casserole dish) with coconut oil or cooking spray. Spread the sweet potato filling in an even layer.

In a medium bowl, combine the rolled oats, chopped pecans, maple syrup, melted coconut oil, cinnamon, and sea salt. Stir until the oats and pecans are fully coated and the mixture begins to clump together.

Scatter the crumble evenly over the top of the sweet potato filling, covering the surface completely.

Bake the casserole at 375°F for 25–30 minutes, until the filling is set and the crumble topping is golden brown and fragrant. If the topping is browning too quickly, tent loosely with foil for the last 10 minutes.

Remove from the oven and allow to cool for at least 10 minutes before serving. The filling will firm up slightly as it cools. Serve warm, scooped with a large spoon.