Preheat oven to 350 degrees. In a large microwaveable bowl, add coconut oil and ½ C chocolate chips. Heat for 2 minutes, stirring every 30 seconds. Whisk sugar into melted chocolate mixture until it begins to dissolve, then add milk and vanilla and combine well. Add the flour and the cocoa to the bowl and stir until just mixed, being careful not to over mix. Add extra chocolate chips. Pour into a prepared 9 x 9 baking pan and bake for approximately 30 minutes. Enjoy!