Preheat oven to 350°F (175°C). Grease mini cake pans and set aside.
In a bowl, whisk together flour, baking soda, cinnamon, nutmeg, cloves, and salt.
In another bowl, combine pumpkin puree and milk.
Beat eggs, granulated sugar, brown sugar, shortening, and vanilla with an electric mixer for 2 minutes until smooth.
Reduce mixer speed and alternately add the flour mixture and pumpkin mixture until combined.
Divide the batter evenly into two bowls.
Melt chocolate chips in the microwave in 30-second intervals, stirring between each, until smooth. Mix melted chocolate into one half of the batter.
Spoon pumpkin batter into the prepared pans.
Add chocolate batter on top.
Then finish with remaining pumpkin batter.
Swirl the layers gently with a toothpick to create a marble effect.
Bake for 20–30 minutes, until a toothpick inserted in the center comes out clean.
Cool cakes completely before frosting.
Beat cream cheese until smooth. Add powdered sugar and vanilla, then mix in milk until the frosting reaches a thick piping consistency.
Pipe cream cheese frosting over cooled cakes and decorate with chocolate sprinkles.