Preheat oven to 350 F. Prepare cupcake baking pan with liners.
In a medium bowl combine flour and baking powder.
In a separate bowl beat butter and cane sugar with mixer until smooth. Add eggs, one at a time. Beat until smooth. Add vanilla extract, milk and sour cream. Beat until all ingredients will combine well.
Add dry ingredients to wet ingredients. Mix with mixer until all ingredients will incorporate well.
Add white chocolate chips and fold in. Pour into 12 muffin liners. Bake for 15 - 20 minutes until inserted toothpick will come out clean.
Remove from oven and cool off on cooling rack.
In a saucepan heat the whipping cream with white chocolate until the chocolate will melt. Cool off completely. It is the best to leave it in the fridge for at least 2 hours.
Beat the whipping cream and chocolate with electric mixer until soft peak. Frost each cupcake.