Preheat the oven to 325º F (about 160º C).
In a medium saucepan over medium-high heat, simmer the cream, the split vanilla bean pod and its seeds, brown sugar, and 1/2 cup granulated sugar, stirring constantly to dissolve the sugar. Remove from the heat as soon as bubbles start forming and gently rising to the surface of the cream mixture. Cover and allow to sit for 20 minutes (steeping technique). Remove the vanilla bean pod.
In a medium bowl, whisk the egg yolks until foamy and lightly discolored. Slowly add 3/4 cup of the hot cream mixture, whisking constantly. Then, add the egg mixture to the remaining hot cream, and whisk (this technique is called tempering). Add the vanilla extract, 1/2 teaspoon cinnamon, nutmeg, and roasted sweet potatoes, and whisk until smooth. Strain through a fine mesh strainer into a large bowl. Divide among 6 - 8 (1/2-cup) ramekins or custard cups.
Arrange the ramekins or custard cups in the metal baking pan. Add carefully enough hot water to come halfway up the sides of the ramekins. Bake in this bain-marie until the custards are just set in the center but still trembling, about 50 minutes. Remove from the oven, let cool down a bit, and refrigerate until well chilled (for at least for 2 hours and up to 3 days).
Remove the crème brûlée from the refrigerator for at least 30 minutes prior to browning the sugar on top. Combine the 6-8 teaspoons of granulated sugar (1 teaspoon per ramekin) with 1 tablespoon cinnamon and a pinch of nutmeg. Sprinkle evenly each custard with 1 teaspoon of the sugar-cinnamon-nutmeg mixture on top . Using a kitchen torch, caramelize the sugar. Alternatively, you can preheat the broiler, and broil for about 1 to 2 minutes until the sugar melts and caramelizes, rotating the cups and watching closely to avoid burning. Let the crème brûlée sit for at least 5 minutes before serving. Do not brulee the dessert more than 20 minutes in advance of serving. Enjoy!
To prepare the Mashed Roasted Sweet Potatoes, use 3 large whole sweet potatoes, scrubbed and patted dry. Preheat oven to 425º F (220º C).
Arrange potatoes in a baking pan, place pan on the middle rack of the oven, and bake for about 80 minutes or until a knife can be inserted in the center of each potato effortlessly. Remove from oven, let cool down for about 15-20 minutes, and peel carefully.
In a medium bowl, mash the potatoes well with a potato masher or fork. Reserve.
** This cooking method will preserve the natural sweetness of the potatoes which is partially wasted when the potatoes are boiled instead.