Line a jumbo (7 cm) 6-count muffin pan with liners and grease the liners generously with butter. Set aside.
Take butter and sugar in a large bowl and beat them using a hand mixer on medium speed until the mixture turns creamy. This will take about 3-4 minutes.
Next, add the vanilla extract, eggs, baking powder, and salt to the butter mixture. Beat using a hand mixer till everything is well incorporated and the mixture turns smooth. This will take about 30-60 seconds.
Now, add half of the flour and gently mix it with a silicone spatula. Mix only till the flour disappears. At this stage, the mixture will be thick. Next, add in the milk and stir everything to combine.
Add the rest of the flour and gently mix it using a silicone spatula. Don’t overmix. (Mix only till the flour disappears)
Add in the chocolate chips (3/4th cup) and gently fold them in using a silicone spatula.
Preheat your oven to 425 degrees F. Let the batter rest while you preheat your oven.
Divide the batter between each muffin cup, filling almost to the top. Tap the muffin pan gently on a hard surface. Sprinkle reserved Choco chips on top (this step is optional, you can add all the choco chips in batter itself if you want).
Bake in a preheated oven at 425 degrees F for 6 minutes, then keep the muffins in the oven and reduce the temperature to 375 degrees (190 degrees c) and bake for another 15-16 minutes or until the top turns golden brown and the toothpick inserted in the middle comes out clean.
Allow them to cool in the pan for 5 to 10 minutes before serving.