Preheat the oven at 220ºC/425ºF conventional oven and line a cupcake tray with 6 cupcake liners, only lining every other cupcake hole, as it helps them to dome up.
In a bowl, sift the all-purpose flour, baking powder and salt together.
160 g all-purpose flour, 1 teaspoon baking powder, ¼ teaspoon baking soda, ¼ teaspoon salt
In another mixing bowl add melted butter, sugar and egg and whisk together until combined.
60 g butter, 100 g granulated sugar, 1 large egg
Then add the whole milk, sour cream and vanilla extract and whisk it together until combined.
50 g sour cream or full-fat plain greek yoghourt, 50 g whole milk, 1 teaspoon vanilla extract
Add the chocolate chips into the sifted flour mixture and mix it together so the chocolate chips are mixed well with the flour. Add the chocolate chips and flour mixture to the wet batter and gently fold it together with a spatula.
125 g chocolate chips
Divide the cake batter into the 6 cupcake liners. Bake them for 5 minutes and then reduce the heat to 175ºC/350ºF, without opening the oven, and further bake for 12-14 minutes.
Let the muffins cool in the hot pan. After 3-5 minutes, gently remove the muffins from the pan and let them cool down additionally for 10 minutes before eating!