Grease 20 mini-muffin cups (or 12 larger ones if you wish). Preheat oven to 400F.
In a large bowl, stir together the flours, sugar, baking powder, baking soda, and salt. In another bowl, stir together oil, juice, liqueur, egg, orange peel, and vanilla. Make a well in the middle of the dry ingredients, add oil mixture, and stir just enough to combine. Stir in chocolate chips.
Divide batter into the 20 prepared muffin cups. Bake about 15 minutes (20 minutes for larger muffins) or until a toothpick/tester comes out clean. Let cool 5 minutes before removing from pans. Serve warm or cold. These store and freeze well.