Place the flour in a microwave-safe bowl, and heat in the microwave for about 40 seconds. In a large bowl, combine butter and sugar until fluffy. Add in milk and vanilla extract, and mix until smooth.
Add in flour, mix until it is fully combined. Fold in the chocolate chips. Evenly press the cookie dough into a baking dish. Place the chocolate chips into a microwave-safe bowl, and heat in the microwave in 30-second intervals, stirring well until it is fully melted and smooth.
Pour the melted chocolate over the cookie dough, and let sit until the chocolate has completely set. Cut into bars and serve.
