Lightly oil 10 inch Bundt pan and preheat oven to 325 F.

In bowl, whisk together flour, cocoa, baking powder, baking soda, and salt.

In bowl of stand mixer, beat baking sticks with sugar until pale and fluffy, occasionally scraping down side of bowl, about 3 minutes. Beat in eggs, 1 at a time, until mixed. Batter will split—that’s okay. Beat in milk and oil. Add flour mixture; beat on low until mixed. Stir in zucchini, chocolate chips, and cranberries.

Spoon batter into prepared pan; smooth top. Bake in center of oven until cake tester inserted in center of cake comes out clean, about 75 minutes. Cool in pan for 15 minutes, then invert onto wire rack set on baking sheet (this will help with cleanup). Cool completely.

Meanwhile, for glaze, place chocolate chips in heatproof bowl. Heat coconut milk until hot; pour over chips. Let stand 3 minutes; whisk to melt chips. Spoon or drizzle half of glaze over top of cake. Add remaining glaze, if needed. Sprinkle with shredded coconut, if using.