Caramelize the white chocolate: Preheat oven to 265 F and pour chocolate into a rimmed baking sheet or pan (I used a 4 oz. and placed it in a small glass container). Place in oven and stir every 5-10 minutes until it has a golden brown hue, about 40 minutes. Remove from oven and place in a bowl. The chocolate should be lumpy/grainy/gross looking, but once you stir it, it should become smooth. Set aside.

Make blondies: Preheat oven to 350 F and line a 9x13" baking pan with parchment paper. In a medium bowl, mix together butter and sugar until combined well. Add eggs and vanilla extract and stir in. Combine flour, salt, and baking powder, and sift into the butter mixture. Fold in and be careful not to overmix. Fold in pecans, and pour into the pan. Drizzle/spoon the melted caramelized white chocolate on the top of the batter and swirl. Bake for 22-25 minutes or until set and baked through. Cool to room temperature and cut into squares.