1/4cup(1/2 stick) unsalted butter, at room temperature
2tablespoonsgranulated sugar
1/4cuppacked light brown sugar
1tablespoonheavy cream or milk
1/2teaspoonvanilla extract
1/2cupall-purpose flour
1/8teaspoonsalt
1/4cupwhite chocolate chips
1/4cupsalted macadamia nuts, chopped
2ounceswhite chocolate, melted
Instructions
For the blondies:
Preheat oven to 350°F. Line an 8x8-inch baking pan with parchment paper, leaving a slight overhang. Butter or spray parchment with nonstick cooking spray.
In a large microwave-safe bowl, melt the white chocolate and butter in the microwave in 30-second bursts, stirring between each burst, until smooth. Stir in sugars. Mixture may appear to separate - that's fine.
Whisk in the eggs and vanilla until combined. Add the flour, baking powder, and salt, stirring until thoroughly combined. Pour batter into prepared baking pan and bake for about 25 minutes, until the top and edges are lightly golden. Transfer pan to a wire rack to cool completely.
For the cookie dough:
In the bowl of an electric mixer, beat the butter and sugars on medium speed until light and fluffy, about 3 minutes. Add the cream and vanilla, beating until combined. On low speed add the flour and salt, beating until combined. With a rubber spatula fold in the white chocolate chips and macadamia nuts.
Spread cookie dough into a thin, even layer over cooled blondies. You may need to use your hands to distribute cookie dough evenly. Place melted chocolate in a small zip-top bag. Cut a small hole in one corner of the bag and drizzle chocolate over blondies. Refrigerate blondies until cookie dough is firm and melted chocolate is set, about 30 minutes.
Use the parchment overhang to remove blondies from pan. Cut into 2-inch squares and serve. Blondies can be stored in an airtight container in the refrigerator for up to 3 days.