In a small mixing bowl, add the flour, cocoa powder, baking powder, and salt.
Mix with a whisk to combine.
Add the egg, milk, and butter/peanut butter.
Mix together until a batter has formed.
Stir through chocolate shards into the batter.
Spoon batter into a medium bowl, smoothing out the top.
In a small bowl, whisk together sugar, cocoa powder, and salt.
Sprinkle over the cake batter.
Pour boiling water over the top.
Microwave for 2-4 minutes depending on thickness of the bowl, until the cake is set and the sauce is thickened.
Let cool for a sec so you don't burn your mouth.
