Preheat the oven to 325 degrees. Place 4 ramekins in a large baking dish.
Pour hot water around the dishes, covering them halfway.
In a medium bowl, whisk together the brown sugar and egg yolks until combined. While whisking, pour in the heavy cream.
Add the pumpkin puree, vanilla, pumpkin pie spice and salt and whisk until fully combined.
Pour the mixture into the ramekins, filling each ⅔ of the way full.
Bake for 35-40 minutes or until just set.
Allow to cool until you can handle them, then transfer to the refrigerator for at least 4 hours, but up to overnight.
Divide the sugar between the ramekins, sprinkling in an even layer.
Caramelize the sugar using a kitchen torch, or place ramekins under the broiler for 2-3 minutes, watching carefully to make sure the sugar doesn't burn.
Serve immediately, or refrigerate until ready to serve.