Preheat oven to 375. Lightly grease an 8x4 inch loaf pan and line with parchment paper.
In a small bowl, melt white chocolate. Set aside.
In another bowl, combine flour and baking powder.
In a medium bowl, whisk sugar and egg. Slowly whisk in melted butter and vanilla.
Combine flour and egg mixture. Stir until smooth. Fold in macadamia nuts, craisins, and extra white chocolate chips (optional). Pour batter evenly into prepared pan.
Bake for 25 minutes or just until golden. Allow it to cool completely in pan on a wire rack. Remove, cut into bars, and enjoy!