Preheat oven to 300° Fahrenheit. Place 8 crème brûlée ramekin dishes in a baking dish or two; set aside.
In a 4 cup or larger measuring cup (you can use a bowl, but it's easier in a measuring cup because you'll be pouring it out later), whisk together the egg yolks and sweetener until well blended and mixture thickens slightly. Set aside.
In a small saucepan, heat the cream and milk over medium-high heat, stirring occasionally to prevent scorching, until just beginning to bubble.
Remove cream mixture from heat and slowly pour into the egg mixture with one hand while briskly whisking with your other hand.
Whisk in the pumpkin puree, pumpkin pie spice, vanilla, salt, and food coloring.
Pour the liquid into the ramekins until about 3/4 full.
Pour cold water into the baking dish around the ramekins so the water rises about halfway up the ramekin dishes.
Pop into the oven and bake for 30 to 40 minutes (give or take, varies based on size, shape, and depth of ramekins) or until mostly set. The center should still be a bit jiggly.
Using a spatula, carefully remove the ramekins from the water and set on a cooling rack.
Cool for about 20 minutes then cover with plastic wrap (be careful not to touch the surface of the custard) and refrigerate for 3 or more hours.
Sprinkle 1/2 to 1 teaspoon granulated sweetener over the top of each chilled crème brûlée. Melt and caramelize this sweetener with a torch until golden brown.
Allow to cool an additional 10 or so minutes so caramelization can harden into a crust.