Preheat the oven to 350 degrees F (175 degrees C). Line 10 cups of a muffin tin with paper liners.

Place sugar and eggs into the bowl of a stand mixer and beat using the paddle attachment until fluffy and pale yellow in color.

Heat milk in a saucepan over medium heat. Bring just to a boil and add white chocolate chips. Whisk until smooth. Pour mixture over sugar mixture and beat for 1 minute. Add vanilla extract and mix until combined. Fold in flour and baking powder using a rubber spoon until just incorporated, being careful not to overmix. Fold in melted butter.

Fill each prepared muffin cup 2/3-full with batter.

Bake in the preheated oven until cupcakes have risen and are just firm to the touch, 20 to 25 minutes. Remove from the oven and transfer to a wire rack to cool.