Heat oven to 350°F. Grease a 9x13-inch baking pan and line with parchment, if desired. (If you plan on serving the cake straight from the pan, no parchment is necessary).

Place zucchini in the bowl of a food processor fitted with the blade attachment. Pulse until you have a mostly smooth puree.

Whisk together the sugar, oil, eggs, and zucchini puree in a large bowl. Sift both flours, cocoa powder, salt, baking powder, baking soda, into the egg mixture. Cut open the chai tea bags and add the tea straight to the bowl.

Mix everything together with a rubber spatula until just combined—don't over mix.

Scrape batter into the prepared pan and bake on the middle rack until a toothpick inserted in the center comes out clean, about 45 minutes.

Let cool on a wire rack at least 20 minutes. If you'd like to remove it from the pan, pull on the outer edges of the parchment paper to take out of the pan.

Combine coconut oil and chocolate in a small saucepan over medium-low heat. Warm, stirring frequently, until chocolate has melted and mixture is smooth.

Transfer chocolate mixture to a large bowl and whisk in milk, vanilla, salt, and powdered sugar until smooth.

Pour frosting over cake and smooth to the edges. Sprinkle with chocolate chips and serve.

Cake will keep covered, at room temperature, for 5 days.