Make the shortbread cookie crust:

1. Preheat the oven to 350F. Prepare a 9-inch square baking pan with 2 sheets of parchment to line every side of the pan. Leave an overhang on the sides to easily lift out the baked bars.
2. In a large mixing bowl, add butter, salt, and vanilla. Use an electric hand mixer to beat together until smooth and creamy. Add in the confectioners’ sugar, then continue to beat for 3-4 minutes, or until pale and fluffy.
3. Add in the baking powder, then spoon in flour in increments while you continue to mix the dough with the hand mixer.  Once all the flour has been fully mixed in, the dough should look soft and slightly crumbly.
4. Gather the dough together then transfer into the prepared baking pan. Use your hands to spread the dough evenly across the pan.
5. Place into the oven to bake for 18 minutes. Remove from the oven and allow to cool to just barely warm.

Prepare the pumpkin pie filling:

1. Turn the oven down to 325F.
2. Add all of the pumpkin pie filling ingredients into a large mixing bowl, then whisk well until smooth.
3. Pour the filling over top of the slightly warm shortbread crust.
4. Place into the oven to bake for 50-55 minutes. When done, the edges should be fully set, but the centre should still be slightly jiggly.
5. Remove from oven and allow to cool to room temperature on the counter. Then place into the fridge for at least 8 hours, or preferably overnight.

Make the whipped cream topping:

1. Use the parchment paper overhand to carefully remove the cold bars from the baking pan and place onto a cutting board. Use a sharp knife to slice into 16 squares.
2. In a medium mixing bowl, add all the whipped cream ingredients including heavy cream, confectioners’ sugar, and vanilla. Beat with an electric hand mixer until stiff peaks form.
3. Place the whipped cream into a piping fitted with a large star tip. Pipe a swirl onto each pie bar. You can also add a dollop of whipped cream to each bar using a spoon instead.