Pre-heat the oven to 170°C/340°F Line a standard 12-hole muffin pan with paper cases.
Mix the vinegar and milk in a large bowl. Let the milk thicken for five minutes, or until it is cooled.
Combine canola oil with eggs, vanilla, and sugars. Add the coffee granules to the hot water and mix. Stir until well combined.
Add flour, baking powder, cocoa, and salt to the bowl. Stir until well combined. Add chocolate chips.
Each paper case should hold 1/3 cup batter. Bake for between 23-25 minutes, or until a skewer inserted in the middle of one muffin comes out clean. Let cool in the pan for 10 mins before transferring to wire rack to cool completely.