Preheat the oven to 375. Spray a muffin tin with cooking spray and set aside.
In a small bowl combine the soy milk and apple cider vinegar. Whisk together then set aside to allow the milk to curdle. This will take about 5 minutes.
Meanwhile, in a medium bowl combine flour, baking powder, baking soda, salt, and cinnamon.
Once milk/vinegar mixture is thick and curdled, resembling buttermilk, add the granulated sugar, oil, and vanilla extract, whisking together until the sugar has completely dissolved. Add the wet ingredients to dry ingredients and mix together until dough is evenly hydrated. Fold in the chocolate chips.
Spoon the batter into the prepared baking sheet so that muffin molds are ⅔rd of the way full. Bake for 20-25 minutes until lightly brown and a knife inserted in the middle comes out clean. Remove from oven and let cool in the muffin tin for 5 minutes before transferring onto wire cooling racks to cool completely.
Store in an airtight container at room temperature for up to 3 days.