Preheat the oven to 325ºF and lightly grease a muffin pan or place cupcake liners in the pan. In a countertop mixer or in a large bowl with a beater, cream together the butter, oil, and sugar until smooth.
In a small bowl stir together milk and vinegar and let sit for about 1-2 minutes, to make sour milk.
Add egg, vanilla, and sour milk to the creamed mixture. Sift flour, almond meal, cocoa, and baking soda into the creamed mixture.
Stir the dry ingredients slowly into the wet ingredients until barely mixed. Add the oil , zucchini, and chocolate chips. Stir until the mixture is just combined.
Evenly distribute the batter into each muffin well until the wells are about 3/4 full. Bake the muffins on the middle rack for about 20-25 minutes, until a toothpick inserted in the center of a muffin comes out clean.