Preheat the over to 325 degrees. In a small saucepan over medium-low heat, stir the cocoa into the butter until melted and smooth.
Mix the flours, baking powder, salt and sugar into a bowl, then add the eggs and stir until moist. Stir in the melted cocoa and add the bourbon (first sampling the bourbon to make sure it is of excellent quality), and finally, stir in the white chocolate chunks.
Scrape the batter into a well-greased 8 x 8 glass baking pan. Place in the oven on the middle rack (along with a cast-iron skillet half-filled with water on the lower rack if you can) and bake 25-28 minutes.
Remove and let cool. Putting some muscle behind it, cut into nine lovely squares and enjoy!