Preheat oven to 350°F. Spray a 10-inch bundt pan with nonstick cooking spray and set aside.
In a medium bowl, whisk together flour, baking soda, pumpkin pie spice, and salt. Set aside.
In the bowl of a stand mixer fitted with the paddle attachment, combine sugar and oil until smooth, about 2 minutes. Add eggs, one at a time, beating well after each addition. Add in the vanilla extract and mix until combined.
Add flour mixture to egg mixture alternately with pumpkin, beating well after each addition. Pour half of the cake batter into the prepared bund pan. Sprinkle the chopped truffles over the batter. Pour the remaining batter over the truffles, making sure they are all covered. Smooth the top with a spatula.
Bake for 60 minutes or until toothpick inserted near the center comes out clean. Remove from oven and place on a wire cooling rack. Cool for 15 minutes before inverting onto the wire rack. Cool cake completely.
While the cake is cooling, make the the chocolate ganache. Place the chopped chocolate in a medium bowl. Heat the cream in a small sauce pan over medium heat. Bring just to a boil, being careful to not let it get to a rapid boil. Pour the hot cream over the chopped chocolate and let sit for 2 minutes. Whisk until chocolate ganache is smooth and silky. Whisk in the corn syrup, this will make the chocolate ganache extra shiny.
Drizzle chocolate ganache over the pumpkin bundt cake. Cut into pieces and serve.
Note-cover the cake and keep on the counter for up to 3 days.