Step 1

Preheat your oven to 375°F. NOTE: you will lower the temperature to 350°F when you start baking. Line a large baking pan with parchment paper.

Step 2

Combine chocolate and butter in a heat-safe bowl and melt in the microwave in short bursts with frequent stirring until completely melted, smooth and glossy. Set aside to cool just slightly.

Step 3

Place egg and sugar in a medium bowl and whisk vigorously for a minute or two until pale and thick. It doesn't need to be extremely aerated - you just want to dissolve most of the sugar into the egg and give it a bit of body. Add the warm chocolate mixture and stir it in until evenly blended.

Step 4

Combine corn starch, cocoa powder, baking powder and salt a small bowl and whisk to combine evenly. Sift your cocoa powder if it is lumpy. Add it to the chocolate mixture and fold it in until evenly combined. Fold in the chocolate chips. Cover the bowl and set it aside for 10-15 minutes to thicken slightly. If it is hot in your kitchen, then refrigerate for just 5-8 minute until the dough is thick and fudgy but not firm. It should still be spoonable and glossy.

Step 5

Scoop up about 1 ½ tablespoons of the fudgy batter onto prepared baking sheets spacing them at least 2 inches apart. Place into the oven and immediately turn the temperature down to Bake for 8-10 minutes until shiny and crackled on top and set around the edges but still a bit soft in the middle. They will continue to set as they cool. Transfer baking sheet to a cooling rack and let cookies cool completely on trays. since they are still delicate while warm.