Sift the flour, baking powder and salt into a large bowl then whisk together and set aside.
In another bowl, add melted butter, milk, and sugar. Whisk thoroughly then microwave for about 40 seconds to remelt the butter.
Whisk in the vanilla extract, eggs, and sour cream.
Add the wet mixture to the dry and mix together until just combined.
Fold the chocolate chips into the batter.
Using an ice cream scooper, add batter to either a buttered and floured muffin tin or a into a tin lined with papers. Using papers is easier for cleanup and removing the muffins but adding the batter directly into the tin gives you that crisp edge that some people crave.
Bake for 5 minutes at 425F then lower temp to 350F and bake for about 20 minutes or until the tops are golden and centers are baked through.
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Notes
Measure your flour correctly! Adding too much flour to the recipe is the most common mistake. The best, and easiest way to measure flour is by using a scale. If you don't have one then fluff your flour with a spoon, sprinkle it into your measuring cup, and use a knife to level it off.
Sour cream packs so much moisture, I know many bakers will add it to every cake recipe because it just works!
The high temperature for the initial part of the bake gives you that domed top that makes these bakery-style muffins.
A drizzle of ganache is a nice way to add a bit of extra decadence to these muffins.