Preheat the oven to 350°F (175°C) and line a cupcake pan with liners.

In a mixing bowl, cream together butter and sugar until fluffy.

Add in eggs one at a time, mixing well after each.

Stir in milk and vanilla extract.

In another bowl, whisk together flour, baking powder, and salt. Gradually add the dry ingredients to the wet ingredients and mix until just combined.

Fold in white chocolate chips.

Fill cupcake liners about 2/3 full and bake for 18-20 minutes or until a toothpick comes out clean.

For the ganache, heat the heavy cream and pour it over chopped white chocolate. Stir until smooth and let cool.

Once cupcakes are cooled, use a knife to cut a small hole in the center of each and fill with white chocolate ganache.

For the frosting, beat together butter and powdered sugar and add vanilla. Pipe onto the cooled cupcakes.