For the biscuits: Preheat the oven to 400 degrees F. Spray two 12-cup mini muffin pans with nonstick spray.
Whisk together the flour, cocoa powder, sugar, baking powder, cinnamon, salt and baking soda in a large bowl. Add the shortening and use your fingertips to pinch it completely into the flour mixture.
Using a box grater, grate the cold butter into the flour. Toss until all the pieces are coated. Pinch and drop the butter pieces in the flour until the butter pieces are flattened and incorporated. Stir in 3/4 cup of the chocolate chips.
Lightly coat your work surface with nonstick cooking spray, then flour. (The spray keeps the flour in place.) Add the buttermilk to the flour mixture. Gently mix the dough with a rubber spatula until there are no dry bits of flour left. The dough should be slightly sticky.
Transfer the dough to the prepared work surface. Lightly coat your hands with flour and gently press the dough with the heels of your hands to form it into a smooth flat rectangle, 1/2 inch thick. Sprinkle the dough with flour, then fold it into thirds (like a letter). Press the dough out again, sprinkle with a little flour and fold it into thirds again, this time folding in the open ends first. Repeat one more time. The dough should no longer be sticky.
Roll the dough out to 1/4-inch thickness. Then cut twenty-four 2 1/2-inch circles out of the dough. Press a circle into each mini muffin cup. Refrigerate until cold, about 15 minutes.
For the pumpkin cream cheese filling: Beat the cream cheese and brown sugar in a large bowl until smooth. Add the egg, then beat on low speed just until combined. Stir in the pumpkin, cinnamon, ginger, nutmeg and salt.
Pour the filling into the biscuit-lined cups. Sprinkle the tops with the remaining 1/4 cup chocolate chips. Bake until the tops are set and the biscuits are golden brown and crisp, about 16 minutes. Let cool 5 minutes before serving.