Preheat Oven: Preheat your oven to 375°F (190°C). Spray Vegetable Cooking Spray on six 8-ounce ramekins and sprinkle with granulated sugar, tapping out the excess. Set aside.
Prepare the Pumpkin Mixture: In a medium saucepan, combine the pumpkin puree, 1/4 cup of granulated sugar, egg yolks, vanilla extract, cinnamon, nutmeg, ginger, and cloves. Cook over medium heat, stirring constantly, until the mixture thickens, about 5-7 minutes. Remove from heat and let cool slightly.
Make the Base: In a small saucepan, heat the milk until just simmering. Whisk in the flour until smooth, then gradually add to the pumpkin mixture, whisking until smooth and well combined.
Beat the Egg Whites In a large mixing bowl, beat the egg whites with the cream of tartar and salt until soft peaks form. Gradually add the remaining 1/4 cup of granulated sugar and continue to beat until stiff peaks form. Gently fold one-third of the beaten egg whites into the pumpkin mixture to lighten it. Then carefully fold in the remaining egg whites until no white streaks remain.
Fill the Ramekins: Divide the soufflé mixture evenly among the prepared ramekins, filling each about three-quarters full. Run your thumb around the inside edge of each ramekin to help the soufflés rise evenly.
Bake: Place the ramekins on a baking sheet and bake in the preheated oven for 25-30 minutes, or until the soufflés are puffed and golden brown on top.
Serve: Remove the soufflés from the oven and dust with powdered sugar. Serve immediately for the best texture.