In a large skillet, melt butter over medium-low heat. When it has completely melted, add vanilla pod and increase heat to medium. Simmer, stirring and scraping with a heat-resistant spatula while butter hisses and pops. When butter is golden yellow and perfectly silent, remove from heat and pour into a medium bowl, making sure to scrape up all the toasty brown bits from along the bottom. Cool until slightly thickened and opaque, but still slightly warm, around 80 degrees F . This will take about 75 minutes at room temperature or 25 minutes in the fridge; if refrigerating, stir butter every 6 minutes or so to prevent it from hardening around the edges of the bowl.
