Preheat the oven to 350 degrees F (175 degrees C) and grease a 9x13-inch cake pan.

In a large mixing bowl, combine chocolate cake mix, chocolate fudge pudding mix, sour cream, vegetable oil, milk, eggs, vanilla extract, and salt. Mix on medium speed for 2-3 minutes.

Pour the batter into the greased cake pan and spread evenly. Bake for 28-32 minutes until a toothpick comes out clean.

Allow the cake to cool in the pan for 30 minutes.

Poke holes in the cooled cake with a wooden spoon handle about 1 inch apart.

In a separate bowl, whisk together chocolate pudding mix and 2 cups of milk until thickened. Pour over the poked cake.

For the frosting, combine heavy cream, powdered sugar, and chocolate pudding mix in a bowl. Whisk on high for 3-5 minutes until thick.

Spread the frosting evenly over the cake.

Crumble the Oreo cookies in a food processor and sprinkle over the frosting.

Use black gel icing to write 'R.I.P.' on Milano cookies and place them on the cake as tombstones.

Press ghost Peeps into the frosting alongside the tombstones, and arrange candy pumpkins around them.

Slice the cake into 12 pieces and serve decorated with candy treats.