Preheat oven to 350°F (175°C). Line a baking sheet with parchment paper.

Beat butter, brown sugar, and granulated sugar until fluffy.

Add egg and vanilla, mixing well.

Whisk flour, baking soda, and salt in a separate bowl. Add to wet mixture.

Fold in white chocolate chips and dried cranberries.

Scoop dough into balls, place on sheet, and bake 9–11 minutes.

Let cool 5 minutes before transferring to a wire rack.