Start by preheating your oven to 350 degrees. While the oven is heating up, prepare an 8×8 baking dish by lining it with parchment paper and generously buttering it.
Whisk the eggs and brown sugar together in a mixing bowl for about 2 minutes. This will create a light and pale mixture.
Add the pumpkin puree, olive oil, vanilla extract, spices (pumpkin pie spice and ground cardamom), and salt to the egg mixture. Whisk everything together until well combined.
Next, add in the flour, baking powder, and baking soda to the wet ingredients. Carefully fold everything together until all of the ingredients are well incorporated.
Pour the batter into your prepared baking dish and bake it in the oven for about 25 minutes. Allow the cake to cool completely before removing it from the pan and frosting.
While your cake is baking and cooling, make the delicious maple buttercream frosting! In an electric mixer, beat room-temperature butter and confectioners sugar on high until light and fluffy.
Then, add the milk, maple syrup, and vanilla extract and whip on high for about 5 minutes. If your frosting becomes too thin or curdles, add in more confectioner sugar until you reach the desired consistency.
To make the cute strawberry ghosts that will top your cake, melt white candy melts or chocolate chips in a bowl. Dip California strawberries into the melted chocolate and dry them on parchment paper.
Once they are dry, melt some milk chocolate chips and use a piping or plastic bag with a small hole cut in the tip to create eyes and a mouth for your ghosts.
Once your cake has cooled completely, spread the maple buttercream frosting over the top. Add crushed chocolate cookies on top for a “graveyard” effect.
Place your strawberry ghosts and other decorations on top of the cake, and then finish it off with a dusting of powdered sugar to resemble snow.