Preheat your oven to 350°F (175°C).
Prepare a 9x13-inch baking pan by greasing it or lining it with parchment paper.
In a separate bowl, whisk together the flour, baking powder, and salt.
In a large mixing bowl, combine the melted butter, brown sugar, and granulated sugar. Mix until smooth and creamy.
Add the eggs and vanilla extract to the butter and sugar mixture. Whisk until smooth.
Gradually add the dry mixture to the wet mixture, stirring gently until just combined.
Fold in the white chocolate chips and dried cranberries until evenly distributed.
Pour the batter into the prepared baking pan and spread it evenly. Bake for 25-30 minutes.
Allow the blondies to cool in the pan for at least 15 minutes before slicing into squares.