Preheat your oven to 325°F (160°C). Carefully cut the tops off each mini pumpkin and scoop out the seeds and pulp. Set the tops aside.
Using a spoon, gently scrape out the flesh, reserving it for the custard, while keeping the pumpkins sturdy enough to serve as bowls.
In a medium saucepan over medium-low heat, combine the pumpkin puree, heavy cream, milk, vanilla extract, sugar, pumpkin pie spice, and salt. Whisk until fully combined and heat until just below a simmer. Do not boil.
In a separate bowl, whisk the egg yolks. Slowly pour the warm cream mixture into the yolks, whisking constantly to temper them.
Strain the mixture for extra smoothness, then pour into the hollowed pumpkins, filling them about 3/4 full. Any extra custard can go into ramekins.
Place the pumpkins in a deep baking dish. Pour hot water into the dish until it reaches halfway up the pumpkins to create a water bath.
Bake for 45–60 minutes or until the custard is set but slightly jiggly in the center.
Remove from the oven and water bath. Let cool slightly, then refrigerate for at least 2 hours or until fully chilled.
To serve with a blow torch: Sprinkle a thin layer of sugar on each custard. Torch until golden and crisp.
To serve without a torch: Combine sugar and water in a saucepan and cook over medium heat without stirring until a golden caramel forms, about 5–7 minutes. Carefully pour a thin layer over each chilled custard and let it harden for 10 minutes before serving.