Prepare the Coconut Cream: Ensure cans of full-fat coconut milk have been thoroughly chilled (at least 12 hours). Carefully open the can(s) and scoop the thick, solidified cream into a medium mixing bowl, reserving the liquid for another use. Measure out 1 ½ cups of solid cream.
Combine Ingredients: Add the pumpkin puree, Homemade Pumpkin Spice Blend, powdered sweetener, vanilla extract, and salt to the bowl containing the coconut cream.
Whip the Mousse: Using an electric hand mixer on medium speed, beat the mixture until it is smooth, fully combined, and noticeably light and fluffy, about 45-75 seconds. Be careful not to overmix.
Taste and Refine: Sample the fluff and adjust the sweetness or spice level if needed, mixing briefly to incorporate.
Assemble Servings: Divide the chopped pecans and pumpkin seeds evenly among 6 small dessert glasses or ramekins, creating a bottom layer. Spoon or pipe the pumpkin fluff mixture over the nut and seed layer.
Garnish and Chill: Top each serving with a dollop of Coconut Whipped Topping and a sprinkle of the remaining nut and seed mixture. Refrigerate for at least 30 minutes before serving to allow the fluff to chill and set slightly.