In a large bowl, use an electric hand mixer to whisk together the vanilla instant pudding mix, cold milk, and sweetener until thickened, following the package directions. Then, fold in the pumpkin puree, pumpkin pie spice, cinnamon, vanilla extract, and a pinch of salt until fully combined and smooth.

Brew the coffee or espresso and let it cool. Pour the cooled coffee into a shallow bowl. Then, lightly dip the ladyfingers in the coffee on one side for just a few seconds, so they absorb some coffee but don’t get soggy or fall apart.

Arrange a layer of 12 soaked ladyfingers in a 9x9-inch baking dish. Spread half of the pumpkin pudding mixture evenly over the top. Add the remaining 12 soaked ladyfingers, then spread the remaining pumpkin mixture on top.

Gently spread just enough whipped topping to cover the surface in a smooth, even layer.

Refrigerate the tiramisu for at least 1 hour before serving to let the flavors meld. Just before serving, dust the top with a pinch of cinnamon and cocoa powder for the perfect finishing touch.