Creating this Pumpkin Sheet Cake is straightforward if you follow these steps:

1. Preheat Oven: Begin by preheating your oven to 350°F (175°C). Grease and lightly flour a 13×18 inch sheet pan.
2. Mix Dry Ingredients: In a large bowl, whisk together flour, sugar, baking powder, baking soda, salt, cinnamon, nutmeg, and ginger.
3. Combine Wet Ingredients: In a separate bowl, combine pumpkin puree, vegetable oil, applesauce, eggs, and vanilla extract. Mix until smooth.
4. Combine Mixtures: Gradually add the wet mixture to the dry ingredients. Stir just until combined; avoid overmixing.
5. Pour Batter: Pour the batter into the prepared sheet pan and spread evenly.
6. Bake: Place in the oven and bake for 25-30 minutes. The cake is done when a toothpick inserted in the center comes out clean.
7. Cool: Once baked, remove from the oven and let it cool in the pan for 15-20 minutes.
8. Prepare Frosting (if desired): For the cream cheese frosting, beat the softened cream cheese and butter until creamy. Gradually add powdered sugar, mixing until fluffy. Add vanilla and enough milk to reach your desired consistency.
9. Frost the Cake: Once the cake has cooled completely, spread the cream cheese frosting evenly on top.
10. Slice and Serve: Cut into squares and enjoy!

These simple steps guide you to a delightful Pumpkin Sheet Cake that will surely impress everyone!