Melt butter and chocolate chips in a medium saucepan over low heat, stirring constantly until smooth.
Remove from heat and let cool for a few minutes.
Stir in sugar.
Add the eggs and mix.
Stir in cocoa powder.
Pour the batter into greased cake pan and bake for about 20-25 minutes.
Cool the cake in the pan for 5-10 minutes, then flip out onto a plate, and carefully flip from the plate onto a cooling rack (this keeps the top of the cake crackly and shiny).
Serve warm with ice cream, or cool completely and dust with powdered sugar or top with whipped cream.
Slice and indulge!
Notes
To make the cake release from the pan easily, spray the cake pan with non-stick spray, press a circle of parchment paper onto the bottom of the pan, and then spray the parchment with non-stick spray. For a thicker cake, use a smaller cake pan and increase the bake time.For a square cake, use an 8x8 baking dish. The bake time does not need to be adjusted.