Preheat the oven to 350 degrees Fahrenheit and line a 7x10” or 8x8” inch baking dish with parchment paper.
Brown the butter: place the butter in a small saucepan over medium heat. Once melted, reduce the heat to medium low and cook for about 15 minutes, stirring frequently until the butter has browned. There should be a slightly nutty smell and brown bits at the bottom of the pan.
Remove the butter from the heat and whisk in the bourbon.
Pour into a large mixing bowl and add the brown sugar and cane sugar. Use an electric mixer to beat for about 1 minute. Add the egg and vanilla and beat again until completely combined.
In a separate mixing bowl whisk together the flour and baking soda.
Pour the flour mixture into the wet ingredients and fold until just combined, then fold in the pecans, white chocolate chips, and dark chocolate chips until well incorporated.
Pour the batter into the prepared baking dish and bake for 20-28 minutes or until a toothpick is inserted and comes out clean or with a few moist crumbs.
Allow to cool completely before slicing and serving.