Preheat your oven to 350°F (175°C). Line an 8x8 inch baking pan with parchment paper.
In a large bowl, whisk together the melted butter and golden monk fruit sweetener until combined. Add the eggs and vanilla extract and whisk vigorously until the mixture is smooth and slightly thickened.
Add the almond flour, baking powder, and salt. Stir with a spatula until a thick batter forms.
Fold in the 1/3 cup sugar-free white chocolate chips and the 1/3 cup chopped macadamia nuts until evenly distributed throughout the batter.
Spread the batter into the prepared pan and smooth the top. Scatter the remaining white chocolate chips and chopped macadamia nuts over the surface, pressing them in gently.
Bake for 22 to 25 minutes, until the edges are golden brown and the center is just set. The white chocolate on top should be softened but not burnt.
Let cool completely in the pan before slicing into 16 squares. The macadamia nuts give these a buttery crunch that pairs perfectly with the creamy white chocolate.