Preheat the oven to 350°. Line an 8 x 8 baking pan with parchment paper and set-aside.

To make the shortbread crust, combine the flour, dark brown sugar, salt, and melted butter in a medium size bowl. Mix all ingredients until dough forms. The dough should be soft but not sticky. Set aside.

To make the filling, place pumpkin in a medium-size bowl. Add eggs, and whisk. Add heavy cream, and whisk again. Add dark brown sugar, vanilla, cinnamon, nutmeg, cloves, and salt. Whisk until completely combined, about 20 seconds.

Press shortbread crust into prepared pan, using the back end of a measuring cup to ensure it is flat and even. Pour filling on top of the crust. Bake at 350° for 50 to 60 minutes, or until edges are golden and middle is set but slightly jiggly. Bars will completely set up as they cool.

Place bars in the refrigerator to completely cool. Before serving, combine the heavy cream and powdered sugar in a medium sized bowl and whip until stiff peaks form. This is easiest with a standing or hand mixer, but can be achieved with a whisk if need be. Spread whipped cream over cooled bars and sprinkle with additional cinnamon if desired. Cut into 16 squares and serve immediately. Enjoy!