In a small bowl, combine the whole milk and white vinegar. Let it sit for about 5 minutes to curdle, creating a homemade buttermilk.
In a microwave-safe bowl, melt 6 tablespoons of the unsalted butter. Allow it to cool slightly before adding it to the batter.
In a large mixing bowl, whisk together the curdled milk, melted butter, vanilla extract, and the large egg until well combined.
In another bowl, whisk together the flour, granulated sugar, salt, baking powder, baking soda, and optional ground cinnamon and cornstarch.
Gradually add the dry ingredients to the wet mixture, stirring gently. Be careful not to overmix; it’s okay if there are a few lumps. Fold in the mini chocolate chips.
Preheat your skillet or griddle over medium heat. Add the remaining 2 tablespoons of butter to the pan, allowing it to melt and coat the surface.
Pour about 1/4 cup of batter onto the skillet for each pancake. Cook until bubbles form on the surface and the edges look set, about 2-3 minutes. Flip and cook for an additional 1-2 minutes until golden brown.
Stack your pancakes on a plate, drizzle with syrup, and extra chocolate chips if desired. Enjoy your delicious stack of chocolate chip pancakes!