Preheat and prep: Heat the oven to 350°F (175°C). Lightly grease a 9x13-inch baking pan or line it with parchment for easy lifting.
Mix the batter: In a large bowl, add the cake mix, pumpkin puree, eggs, oil, milk, vanilla, cinnamon, nutmeg, ginger, and salt.
Whisk until just combined and smooth. Avoid overmixing.
Bake: Pour the batter into the prepared pan and smooth the top. Bake for 25–32 minutes, or until a toothpick inserted in the center comes out clean with a few moist crumbs.
Poke the cake: Let the cake cool for 10 minutes.
Using the handle of a wooden spoon or a large straw, poke holes all over the cake, spacing them about 1 inch apart.
Make the soak: Warm the caramel sauce until pourable. If using, stir in the sweetened condensed milk for a richer soak.
Soak the cake: Slowly pour the caramel mixture over the cake, aiming to fill the holes. Use a spatula to nudge caramel into any dry spots.
Let the cake cool to room temperature, then chill for at least 1 hour.
Whip the topping: In a cold bowl, beat the heavy cream, powdered sugar, and vanilla until medium-stiff peaks form. Don’t overbeat.
Finish and garnish: Spread the whipped cream over the chilled cake. Sprinkle with toasted pecans and drizzle with more caramel.
Serve: Slice and serve chilled or slightly cool.
Wipe the knife between cuts for clean slices.