Preheat the oven to 350°F and coat a 9x13-inch baking pan with nonstick spray.
cooking spray
Cook the bacon in a sauté pan over medium heat until crisp. Drain on a paper towel-lined plate, and set aside. Reserve two tablespoons of the drippings.
8 oz raw bacon, diced
In a medium bowl, whisk together the flour, baking soda, cinnamon, and table salt for the bars, then set aside
2 cups all-purpose flour, 1 tsp baking soda, 1 tsp ground cinnamon, 1/2 tsp table salt
In a large bowl, whisk together the pumpkin puree, granulated sugar, 1/2 cup brown sugar, egg, melted butter, bacon drippings, and vanilla until well blended. Stir in the flour mixture and pecans.
1-1/2 cups pumpkin puree, 1/2 cup granulated sugar, 1/2 cup packed light brown sugar, 1 large egg, 2 tbsps unsalted butter, melted, 2 tbsps reserved bacon drippings, 1 tsp vanilla extract, 1/4 cup chopped pecans
Spread the pumpkin batter evenly into the prepared pan and bake until a toothpick inserted into the center comes out clean, about 20 minutes. Let cool completely before frosting.
In a large saucepan, boil 2 cups of brown sugar, water, and a pinch of salt for the frosting over high heat for 5 minutes, swirling occasionally to prevent scorching. Whisk in the cream and butter pieces (the mixture will bubble furiously, so keep whisking) and boil for 2 more minutes.
2 cups packed light brown sugar, 1/3 cup water, pinch of table salt, 1/2 cup heavy cream, 4 oz unsalted butter, cubed
Transfer the caramel to the bowl of a stand mixer and whip on high speed until the sides of the bowl are cool to the touch and the caramel is thick, about 10 minutes, scraping down the sides of the bowl as needed. Add the cream cheese, one cube at a time, until the frosting is smooth.
4 oz cream cheese, cut into 1" pieces