Preheat your oven to 425°F (220°C) to achieve the perfect rise and golden-brown top.
Line your jumbo muffin tin with paper liners or grease it lightly with cooking spray.
In a large mixing bowl, whisk together the all-purpose flour, baking powder, baking soda, granulated sugar, and salt until well combined.
In a medium bowl, whisk together the buttermilk, pure vanilla extract, vegetable oil, and the large egg until smooth.
Pour the wet ingredients into the dry ingredients and gently fold the mixture using a spatula until just combined.
Fold in the semi-sweet chocolate chips until evenly distributed.
Fill each muffin cup to the top with batter for that signature bakery-style dome.
Bake for 5 minutes at 425°F (220°C) then reduce to 350°F (175°C) and bake for an additional 15-20 minutes.
Let the muffins cool in the tin for about 5 minutes before transferring them to a cooling rack.
