Preheat oven to 350F; grease a standard bundt cake pan with butter.
Whisk together the flours, cocoa powder, salt, baking powder, baking soda, and tea (from the opened tea bags) together in a large bowl; set aside.
Beat together the sugar, eggs, and oil until fluffy, then beat in the zucchini, molasses, and vanilla.
Add the dry ingredients to the wet all at once and whisk until just combined, being careful not to over-mix.
Pour the batter into the prepared pan and bake until a wooden pick inserted in the center comes out clean, about 1 hour, 15 minutes.
Place the pan on a wire rack and cool completely in the pan, then run a knife along the outside of the cake invert it onto a platter to remove it.
Before serving, sprinkle with a dusting of powdered sugar if desired.