Preheat the Oven: Set your oven to 350°F and grease a 9x13-inch baking pan.
Mix the Batter: In a large bowl, combine the cake mix, pumpkin puree, brown sugar, cinnamon, ginger, and nutmeg. Stir until smooth.
Bake the Cake: Pour the batter into the prepared pan and spread it evenly. Bake for 25-30 minutes, or until a toothpick inserted into the center comes out clean.
Poke Holes: Let the cake cool for about 15 minutes. Use the handle of a wooden spoon to poke holes all over the cake.
Add Sweetened Condensed Milk: Pour the sweetened condensed milk over the cake, making sure it seeps into the holes. Let the cake cool completely.
Top the Cake: Spread the whipped topping evenly over the cooled cake. Drizzle with caramel sauce and sprinkle with toffee bits.
Chill and Serve: Refrigerate the cake for at least 3 hours before serving. This helps the flavors meld together and makes the cake easier to slice.