Start by preheating your oven to 350 degrees Fahrenheit. As the oven warms up, prick each sweet potato multiple times with a fork or knife. This allows steam to escape while baking, preventing any bursting.
Place the prepared sweet potatoes on a baking sheet and bake for about 30 minutes, or until they’re soft. If you're in a rush, you can also microwave them on high for 13 to 15 minutes.
Once cooked, remove the sweet potatoes from the oven. Let them cool for a few minutes, then carefully slice each one in half lengthwise. Use a spoon to scoop out the centers into a bowl, leaving about a 1/4 inch border of sweet potato in the skin.
In the bowl with the scooped sweet potato, mix in brown sugar, butter, salt, and cinnamon until the mixture is smooth and creamy. This is where the magic happens!
Using a large tipped pastry bag or simply a spoon, pipe the creamy filling back into the hollowed sweet potato skins. Make sure to fill them generously!
In a separate small bowl, combine the remaining ingredients for the streusel: flour, chopped walnuts, brown sugar, and butter. Mix together until the butter starts to warm and the ingredients begin to stick together.
Sprinkle the streusel mixture generously over the filled sweet potatoes. This topping will create a fabulous contrast with the creamy filling.
Return the filled and topped sweet potatoes to the oven and bake for an additional 20 to 30 minutes, until everything is heated through and the tops are golden brown.
Once baked, remove them from the oven and let them cool slightly before serving. Enjoy your Twice Baked Sweet Potatoes warm!
