Best Sweet Potato Casserole with Marshmallows

For the Mashed Sweet Potato Base:

• 3 pounds sweet potatoes washed (about 3-4 large sweet potatoes)
• 4 tablespoons unsalted butter melted (for making it dairy-free, use dairy-free butter or coconut oil)
• ⅓ cup half-and-half or whole milk which is full-fat. NOTE: To make it dairy-free, replace it with unsweetened soy milk or almond milk but you may have to reduce the amount of liquid slightly to not make your mashed sweet potato base watery. A full-fat liquid helps with a thick consistency and a richer flavor.
• ½ cup light brown sugar Use Brown Swerve for a low-carb or sugar-free dish!
• 1 teaspoon cinnamon
• ¼ teaspoon ground nutmeg optional
• 2 large eggs lightly beaten
• 1 teaspoon pure vanilla extract
• ½ teaspoon table salt

For the Topping:

• ½ cup light brown sugar or Brown Swerve to make it sugar-free or low-carb.
• ¾ cup oat flour , certified gluten-free. If you don't have oat flour you can make your own by grinding rolled oats in a food processor until obtaining a flour texture. NOTE: If you aren't a celiac, you may replace oat flour with ½ cup of all-purpose flour.
• ¾ teaspoon cinnamon
• Pinch table salt
• 6 tablespoons unsalted butter melted (you may use coconut oil if you prefer to make it dairy-free)
• 1 ¼ cups Chopped Pecans for a nut-free casserole, use sunflower seeds instead
• 2 cups miniature marshmallows you may replace them with the toasted meringue topping below. Or for a low-carb/sugar-free version, use sugar-free marshmallows.

Alternative Topping (Toasted Meringue):

• 2 eggs separated (yolks from whites)
• ⅛ teaspoon cream of tartar
• ½ cup powdered sugar