02Grease a 9"x13" baking pan (preferably glass), and dust generously with cocoa powder, tapping out excess.
03Sift together the cocoa powder, flour, baking soda, salt, cloves, and cinnamon, and optional nutmeg, and set aside.
04Cream together the butter, oil, and sugar until fluffy, add eggs, vanilla, and sour milk, and blend well by hand.
05Add drained and squeezed grated zucchini, and stir in well.
06Spoon the batter evenly into the prepared pan.
07Sprinkle the top evenly with chocolate chips, leaving a chip-free 1" diameter area right in the center, and then sprinkle evenly with chopped pecans.
08Bake for about 45 minutes or until a toothpick inserted in the center comes out clean.
09(That’s what the chip-free spot is for. You will never get a clean toothpick otherwise; it will always be chocolate covered.) If you are using a metal pan, bake at 350degF for 40 minutes.
10Allow to cool to room temperature in pan sitting on wire rack.
11If desired, serve with a dollop of very lightly sweetened whipped cream.
12Refrigerate or freeze leftover cake; this cake is very moist and will mold if left for long at room temperature, but it won't get stale!