Using an electric mixer, beat the egg yolks, 1/4 cup of the erythritol, and the vanilla together until thick and pale.
To a medium saucepan, over medium heat, add the heavy cream, almond milk, pumpkin pie spice and salt. Heat until bubble start to form around the edges of the pan.
Remove the cream mixture from the heat and gently whisk the egg mixture into the cream, stirring continuously. Then, whisk in the pumpkin puree. Taste and add additional sweetener, if desired.
Place 4 x 4 ounce ramekins in a deep roasting pan. Add boiling water to the roasting pan until it reaches halfway up the sides of the ramekins.
Divide the pumpkin spice custard mixture evenly among the 4 ramekins.
Loosely cover the roasting pan with foil and bake for 45 to 50 minutes, or until the center of the creme brûlées are set, but still jiggle slightly. They will continue to firm up after baking. Take the ramekins out of the water bath and allow to cool for 10 minutes.
Cover the ramekins with plastic wrap and cool in the refrigerator for 3 hours, up to 24 hours.
Before serving, add the remaining erythritol over top of the creme brûlées and using a brûlée torch, carefully melt the sweetener until it turns to toffee. Garnish with a sprinkling of pumpkin spice mix.