Preheat the oven to 350℉. Oil a 9 x 13 pan and line bottom and sides with parchment paper with enough paper to lift the blondies out of the pan. Set aside.
In a small microwaveable dish, add butter and 1 cup white chocolate chips. Heat for 30 seconds. Stir and heat in 10 second increments until just melted. Cool to room temperature.
In a large mixing bowl, add sugar, eggs and vanilla. Beat until thick and cream colored, about 2-3 minutes.
Add melted butter/chocolate mixture, flour, salt, macadamia nuts and remaining white chocolate. Beat until just combined, scraping down sides.
Spread mixture into the prepared pan and bake until a tooth pick inserted in the center comes out clean, about 20 minutes.
Let cool for 5 minutes, cut into 24 bars. Move bars to a cooling rack and let cool completely.