Ingredients
Equipment
Method
- Heat the oven to 350 F and set a rack in the center. Leave the 15x10x1 inch jelly roll pan ungreased.
- In a large bowl, whisk the flour, baking powder, baking soda, cinnamon, pumpkin pie spice and salt until evenly combined. Set aside.
- In a second large bowl, whisk the eggs, granulated sugar and brown sugar until the mixture lightens slightly, about 1 minute. Whisk in the oil, pumpkin puree and vanilla until completely smooth with no streaks of pumpkin.
- Add the dry mixture to the wet and stir with a rubber spatula just until the last of the flour disappears. Do not use a mixer here and do not beat. Overmixing whips in air that expands and collapses, sinking the center.
- Pour the batter into the ungreased pan. It will look thin. Spread it into the corners with an offset spatula and level the top.
- Bake 25 to 30 minutes, until the surface springs back when pressed lightly and a toothpick inserted in the center comes out clean with no wet batter.
- Set the pan on a wire rack and cool completely, at least 1 hour. Frosting a warm slab will melt it straight off the edges.
- Beat the softened cream cheese, butter and vanilla with an electric mixer on medium until fluffy and no lumps remain, about 2 minutes.
- Add the powdered sugar 1 cup at a time on low speed, then beat on medium until smooth and spreadable, about 1 minute more.
- Spread the frosting evenly over the cooled slab with an offset spatula, working all the way to the edges.
- Refrigerate uncovered about 1 hour, until the frosting sets firm. Cut into 24 squares with a clean knife, wiping the blade between cuts. Serve chilled or at room temperature.
