Preheat the oven to 350°F degrees. Spray a 17x11 baking sheet with baking spray, set aside. In a medium-sized bowl stir together the flour, baking soda, pumpkin spice, and salt, set aside.

Place the pumpkin, granulated sugar, oil, and eggs into a large bowl. Whisk until combined. Slowly stir the dry ingredients into the wet until just combined, with no dry patches.

Pour mixture into the prepared baking sheet. Bake for 18-20 minutes until a toothpick inserted into the center comes out clean. Place on a wired rack and let cool completely.

Cream the cream cheese and butter together in a large bowl with an electric hand mixer until smooth.

Add the vanilla, mix to combine. Add the powdered sugar in ½ Cup at a time until fully incorporated. Scrape down the sides. Whip the frosting for 2 minutes on medium-high speed until light and fluffy.

Once the cake is cooled, frost the top of the sheet cake.

Place the heavy cream, sugar, brown sugar, pumpkin spice, butter, corn syrup, baking soda, and salt into a medium-sized saucepot. Bring to a boil over medium-high heat, reduce to low. Stir occasionally. Simmer on low for 6 minutes. Take off the heat, add in the vanilla, let cool slightly.

Drizzle over the cake while it is still warm, enjoy!