Chop the white chocolate bar into chunks.

Place the white chocolate in a small bowl and microwave in 30-second intervals for 2 minutes or until melted.

In a bowl, whisk together the flour, baking powder and salt.

In a standing mixer, beat together the butter and sugar on medium speed for 3-4 minutes.

Scrape down the sides of the bowl and add the egg and vanilla. Mix again.

Pour the melted and slightly cooled white chocolate and mix

Add the flour, baking powder and salt mixture and mix a final time until the dough just comes together.

Place a piece of plastic wrap on the counter and put half of the dough on it. Cover the entire ball of dough and gently pat into a disk.

Repeat with remaining dough and place in the fridge for 1 hour or up to overnight.

Preheat the oven to 350 degrees.

Line a baking sheet with parchment paper.

Unwrap the dough and sprinkle a little powdered sugar on the counter to avoid sticking.

Using a rolling pin dusted with powdered sugar, roll the dough out to ½" thick.

Using cookie cutters, cut the dough and place on the baking sheet.

Bake for 10-12 minutes and remove from the oven, repeating with remaining dough.

Meanwhile, prepare the icing.

In a bowl, add the powdered sugar, corn syrup, peppermint and water. Mix together until smooth, shiny and when you lift the spoon a ribbon of icing stays on the top of the icing before finally melting back in.

Frost cookies using a piping bag and small tip. Add sprinkles if desired.