Preheat oven to 425°F (218°C) and grease a 12-cup muffin tin or line with paper liners.

In a large mixing bowl, whisk together the flour, baking powder, salt, and granulated sugar.

In a separate medium bowl, whisk the melted butter, milk, eggs, and vanilla extract until well combined.

Create a well in the dry ingredients and pour in the wet mixture; fold gently with a spatula until just combined, ensuring not to overmix.

Fold in 200g of the chocolate chips until evenly distributed.

Divide the batter evenly among the 12 muffin cups, filling them to the very top.

Press the remaining 50g of chocolate chips into the tops of the muffins.

Bake at 425°F (218°C) for 5 minutes, then, without opening the oven door, reduce the temperature to 375°F (190°C) and bake for an additional 13-15 minutes until a toothpick comes out clean.

Allow muffins to cool in the pan for 5 minutes before transferring to a wire rack to cool completely.