Step 1: Roast the Sweet Potatoes

Start by roasting the sweet potatoes. Preheat your oven to 400°F (200°C). Pierce the sweet potatoes with a fork a few times, then place them on a baking sheet lined with parchment paper. Roast them for about 45 minutes, or until they’re soft and easily pierced with a fork. Once done, let them cool slightly before peeling the skin off. Mash the sweet potato flesh until smooth using a fork or a blender. You’ll need about 2 cups of mashed sweet potatoes for the crème brûlée.

Step 2: Prepare the Custard Base

In a medium saucepan, combine the heavy cream, whole milk, and cinnamon (if using). Heat the mixture over medium heat, stirring frequently, until it’s warm but not boiling. Remove from heat and set aside.

Step 3: Mix the Egg Yolks and Sugar

In a separate bowl, whisk together the egg yolks, ½ cup of granulated sugar, and a pinch of salt. Whisk until the mixture becomes pale and thick. Slowly pour the warm cream mixture into the egg yolk mixture, whisking constantly to avoid scrambling the eggs. Once everything is well combined, add in the mashed sweet potato and vanilla extract. Mix until smooth.

Step 4: Strain the Custard

To ensure the custard is perfectly smooth, strain the mixture through a fine mesh sieve into another bowl. This will remove any lumps or bits of sweet potato skin, giving you a silky custard.

Step 5: Bake the Crème Brûlée

Preheat your oven to 325°F (160°C). Place your ramekins in a large baking dish and fill each with the sweet potato custard. Carefully pour hot water into the baking dish until it comes halfway up the sides of the ramekins. Bake for 45 to 50 minutes, or until the custards are set but still slightly jiggly in the center.

Once baked, remove the ramekins from the water bath and let them cool to room temperature. Then refrigerate them for at least 2 hours or overnight.