For Pumpkin Panna Cotta, put 1/2 cup of the milk and the sugar in a medium saucepan, then sprinkle the gelatin over it. Let sit for 5 minutes. Meanwhile, blend together the remaining milk, cream, pumpkin, and cinnamon. Turn the heat under the saucepan to low, and cook the milk, stirring occasionally, until the gelatin dissolves. Pour in the cream mixture, and turn the heat to medium. Cook, stirring occasionally, until steam rises. Turn off the heat, and ladle or pour the mixture into 8 4-ounce ramekins or other containers and chill until firm.
For the Pepitas, first preheat oven to 350F. Stir together all ingredients in a bowl. Spread mixture in a single layer on a baking sheet lined with parchment. Bake until pepitas are golden and crisp, about 10-12 minutes.
For the Spiced Caramel, bring sugar and ¼ cup water to a boil in a large saucepan over medium-high heat, stirring to dissolve sugar. Cook until a deep amber color, 8–10 minutes. Reduce heat to low; add butter and stir until smooth. Stir in cream, spices and salt and stir until smooth.
To serve: turn panna cottta out onto plate, drizzle on caramel, and top with pepitas.