Preheat the oven to 350ºF (177ºC) and prepare three 6-inch or two 8-inch cake pans by spraying the sides with baking spray and placing a parchment paper circle into the bottom of each one.

In a medium bowl, whisk together the all-purpose flour, baking powder, baking soda, salt, cinnamon, allspice, nutmeg, and ground ginger. Set aside.

In a separate large bowl, add the brown sugar, granulated sugar, oil (if using melted butter in place of the oil, cool it for 5-10 minutes prior to adding here), eggs, pumpkin puree, and vanilla extract. Whisk together until uniform, then add the flour mixture and whisk until smooth.

Pour the batter evenly between the prepared cake pans and bake for 32-36 minutes, until a toothpick inserted comes out clean or with just a few moist crumbs. Cool the cakes in the pan for five minutes before removing and transferring to a wire rack to cool completely to room temperature.

In the bowl of a stand mixer fitted with the paddle attachment, beat the butter on high speed until creamy and smooth, about 5 minutes.

Add half of the powdered sugar and mix on medium speed until it resembles coarse sand. Mix in the vanilla, followed by the rest of the powdered sugar. It will continue to look sandy and clumpy at first and then will eventually combine into a very thick mixture that almost resembles pie dough.

Add the cream cheese and salt and mix on low speed until combined, then turn the mixer to high speed and beat for about 1 minute until the frosting is smooth.

Once the pumpkin cake layers have cooled completely, level them to your desired height. Add a swipe of cream cheese frosting onto a cardboard cake round and place one of the cake layers on top. Add cream cheese frosting on top of the cake layer and smooth it down until it’s about ½ inch tall, then place the next cake layer on top and repeat.

When you reach the final cake layer, place it upside down so that the bottom of the layer is the top of the cake. Then, crumb coat the cake with a thin layer of cream cheese frosting and refrigerate the cake for 15-20 minutes to let the crumb coat firm up.

Use the cream cheese frosting to create a smooth buttercream finish on the cake and press the Biscoff cookie crumbs onto the bottom third of the cake.

Divide the remaining cream cheese frosting amongst four small bowls. Add orange food coloring to the first bowl, dusty blue food coloring to the second bowl, chocolate brown to the third bowl, and keep the fourth bowl uncolored.

Fit a piping bag with Wilton Tip 6B and fill it with the orange frosting, then fit two piping bags with Wilton Tip 4B and fill one with the white frosting and one with the blue frosting. Fit a final piping bag with Wilton Tip 3 and fill it with the brown frosting.

On the top of the cake, use the piping bag with the orange buttercream to pipe pumpkins of various sizes in a crescent shape. Fill in the spaces of the crescent shape with white and blue pumpkins. Finish the look by piping stems on each pumpkin using the brown frosting.