Roast whole sweet potatoes at 400°F for 45-50 minutes before pureeing to concentrate their natural sweetness and reduce excess moisture, resulting in a creamier, richer casserole base.

Dry toast pecans in a 350°F oven for 8-10 minutes before chopping and adding to the topping to unlock their oils and deepen their nutty flavor profile.

Warm your cinnamon and nutmeg in melted dairy-free butter for 30 seconds before mixing into the sweet potato mixture to activate their essential oils and distribute flavor evenly throughout.

Sprinkle marshmallows only in the last 5-8 minutes of baking so they toast to golden perfection without burning; too early causes over-browning, too late leaves them unmelted.

Refrigerate the assembled casserole for at least 2 hours before baking to allow flavors to meld and ensure the sweet potato mixture sets properly, creating a smoother, more cohesive texture.