2/3cupchocolate malted milk eggscrushed (such as Whopper’s Robin’s Eggs)
Preheat the oven to 350°F. Line an 8x8-inch square baking pan with 2 sheets of foil, crossing the sheets one over the other, allowing each strips of foil to overhang the sides of the pan. Press the foil into the corners and up the side. Lightly grease the foil with butter or cooking spray and set aside.
Whisk the cocoa powder in 1/4 cup boiling water in a large heatproof bowl until smooth. Add the semi-sweet chocolate, butter, and oil to the bowl with the cocoa powder mixture.
Fill a medium saucepan with 1'' of water, and bring to the water to a simmer (not boiling) over medium heat on the stovetop. Place the bowl with the ingredients in it on top of the saucepan, making sure the bottom of the bowl isn't touching the water. Allow the rising heat from the water to gently warm the mixture, stirring occasionally until the chocolate and butter are melted and the mixture is smooth. Remove the bowl from the pan and let cool until lukewarm.
Whisk the sugars into the melted chocolate mixture. Add the egg, egg yolks, and vanilla, and whisk vigorously until the mixture is very thick, smooth, and glossy. Add the flour, milk powder and salt. Whisk together until everything is combined, then whisk vigorously until the batter is very thick, about 45 seconds. Fold the chopped milk chocolate into the batter with a flexible spatula.
Scrape the batter into the prepared pan, spreading in an even layer all the way into the corners. Bake 25-30 minutes, until the surface of the brownies is shiny and crackled. The brownie will still be a little soft in the center. Allow the brownies to cool in the pan about 1 hour. Refrigerate for one hour.
Lift the brownie from the pans using the ends of the foil and place on a large piece of parchment or foil. Transfer the melted white chocolate to a zip-top bag with the corner snipped. (Or use a disposable piping bag.) Drizzle white chocolate over the brownie block and immediately top with crushed malted milk eggs. Let stand 10 minutes until set. Cut brownie into 12 to 16 squares.
This recipe was adapted from the Epicurious recipe "Malted Forever Brownies" by Claire Saffitz.