How to Make It
Preheat oven to 350°.
Place zucchini on several layers of paper towels; cover with additional paper towels. Let stand 10 minutes, pressing down occasionally.
Weigh or lightly spoon flour into dry measuring cups; level with a knife. Combine flour, 6 tablespoons cocoa, and next 3 ingredients (through 1/4 teaspoon salt) in a medium bowl, stirring with a whisk.
Place granulated sugar and next 4 ingredients (through vanilla) in a large bowl; beat with a mixer at medium speed until lemon-colored (about 5 minutes). Add eggs, 1 at a time, beating well after each addition. Add flour mixture to sugar mixture; beat at low speed 1 minute or just until combined. Add zucchini and chocolate chips; beat at low speed 1 minute or just until combined. Spoon batter into a 9 x 5-inch metal loaf pan coated with baking spray. Bake at 350° for 38 minutes or until a wooden pick inserted in center comes out clean. Cool in pan 10 minutes on a wire rack. Loosen edges from sides using a narrow spatula. Remove from pan, and cool completely on wire rack.
Combine powdered sugar, remaining 1 tablespoon cocoa, milk, and dash of salt in a small bowl, stirring until smooth. Drizzle over loaf.
BAKE A SECOND BATCH If you have two loaf pans available, then double the mix. Cool and wrap baked cakes whole and unglazed in plastic wrap. To ship overnight, pack securely in a box, or gather a pretty cloth around the cake to hand-deliver. The icing is wet; pour it into a zip-top bag and include instructions to snip the corner and drizzle onto the cake.