Prepare the Crust:Preheat the oven to 350°F. Line a 13 x 9-inch pan with aluminum foil and spray with non-stick cooking spray.
Place the walnuts in a food processor and pulse until they are finely chopped. Transfer to a medium bowl and stir in the flour, sugar, cinnamon, and salt. Add the melted butter and combine well.
Press the dough into the prepared pan to form an even crust. Bake for 15 to 18 minutes or until it just starts to brown on the edges.
Prepare the latte layer:In the mixer fitted with the paddle attachment, combine the butter, cream cheese and sugar on medium speed until fluffy, 8 to 10 minutes. Add the eggs, flour, vanilla, cinnamon and nutmeg. Do not over mix.
Pour the cream cheese batter over the prepared crust. Sprinkle with half of the walnuts, allowing them to fall into the batter. Place the pan in the oven and bake for about 20 minutes.
Prepare the pumpkin layer: Meanwhile, in a medium bowl, whisk together the pumpkin, eggs, granulated sugar, brown sugar, ginger, cloves, salt, heavy cream and milk. Spoon the pumpkin layer gently on top of the partially cooked cheesecake layer and bake for an additional 30 to 35 minutes.
Remove from the oven and cool fully, about 1 hour. Use the foil to remove the bars from the pan. Slice into 24 uniform bars by cutting 4 long columns and 6 rows.
Whip the other ½ cup of cream into medium peaks. Top each bar with a dollop of whipped cream and sprinkle with remaining walnuts.