01 -
Preheat the oven to 350°F and spray an 18x13x1-inch sheet pan with baking spray.
02 -
In a medium bowl, combine flour, baking soda, pumpkin pie spice, cinnamon, salt, and nutmeg; set aside.
03 -
In a large bowl, whisk together pumpkin puree, light brown sugar, granulated sugar, vegetable oil, eggs, and vanilla extract until smooth.
04 -
Gradually incorporate the dry ingredients into the wet mixture, stirring just until fully combined with no dry streaks.
05 -
Pour batter into prepared sheet pan, smoothing the surface evenly, and bake for 18-20 minutes or until a toothpick comes out clean.
06 -
Melt butter in a small saucepan over medium-low heat. Stir in dark brown sugar and heavy cream, whisking continuously until the mixture reaches a boil.
07 -
Remove from heat and whisk in powdered sugar in increments until fully combined. Stir in bourbon and vanilla extract.
08 -
Fold in toasted chopped pecans and salt to the icing mixture.
09 -
Pour the icing slowly and evenly over the slightly cooled cake, taking care not to overflow. Allow icing to set for about 1 hour before slicing.