Preheat oven to 170 degrees C. Grease and flour 18 muffin cups or use patty cups. Mix together the flour, bicarb soda, salt, cinnamon, nutmeg and hot chocolate mix. Set aside.
In a large bowl, cream together the butter, olive oil and sugar until light and fluffy. Beat in the eggs one at a time, then stir in the milk and vanilla. Beat in the flour mixture, just until incorporated. Stir in the grated zucchini and chocolate chips. Pour batter into prepared pan.
Bake in the preheated oven for 25 to 30 minutes, or until the top of the cupcakes springs back when lightly pressed. Cool in pans over a wire rack for at least 10 minutes before removing. They are really gooey fresh from the oven!