Photo: Brian Woodcock; Styling: Claire Spollen
Serves 16 (serving size: 1 wedge)
Preheat oven to 350°. Combine semisweet chocolate, canola oil, and butter in a bowl. Microwave at HIGH 45 seconds, stirring occasionally. Stir in brown sugar, granulated sugar, and egg. Stir in flour, cocoa, baking soda, and salt. Stir in chopped milk chocolate. Scrape into a 10-inch cast-iron skillet. Bake at 350° for 19 minutes.