In a large bowl, whisk the egg yolks and sugar until just combined.
Net, whisk in the pumpkin purée, vanilla extract, and pumpkin pie spice.
In a saucepan over medium heat, bring the heavy cream to a simmer and immediately take it off the heat. Slowly pour the heavy cream into the egg mixture, whisking constantly so the hot cream doesn't cook the eggs.
Strain the hot custard through a fine-mesh sieve to catch any clumps that may have accumulated.
Preheat the oven to 325°F. Place the ramekins into a deep baking dish and evenly distribute the custard into each. Next, fill the baking dish with just enough water that it reaches halfway up the sides of the ramekins. Next, carefully transfer the baking dish onto the middle rack of the oven and bake for 15-30 minutes. Allow the creme brulee to cool down at room temperature. Transfer them into the refrigerator for at least two hours.
Sprinkle a small spoonful of sugar on top of each creme brulee. Using a kitchen blowtorch, caramelize the sugar on top of each custard. The best way to get even caramelization is to move the torch slowly and consistently, versus keeping it directed in one place (this will burn the custard and sugar).