In a bowl, whisk the flours, sugar, baking powder, cinnamon, nutmeg, and salt. With your fingers toss in the butter and break up until the mixture resembles damp sand.
Whisk the egg and buttermilk in a bowl. Add the zucchini and chocolate. Make a well in the center of the flour mixture and pour all of the buttermilk mix in at once. Toss with a wooden spoon until everything is just moistened.
On a clean lightly floured surface, turn the dough out and sprinkle with a bit of flour so you can handle. Knead it a few times to form a ball. Transfer to a parchment paper-lined baking sheet.
Cut the dough into 6 pieces and spread out from one another about 2 inches.