Double Chocolate Brownies

Baloney wanted to make this for a friend's birthday. I was surprised that his mom asked for the recipe because I don't consider myself much of a brownie maker but I am not much of a brownie eater so I don't know if I am the best judge of a great brownie recipe.
It is from the Mrs. Fields cookie book but I altered it. Originally it was called Carmel-Filled Brownies. It has a caramel center but Baloney did not know if his friend liked caramel so we played it safe with the chocolate chip substitute.
3 oz. unsweetened chocolate
1/2 c. butter
4 eggs
1 1/2 c. white sugar
1 tbsp vanilla
1 1/2 c. flour
1 c. chocolate chips
Preheat oven 350 degrees. Oil 8x8 baking pan.
Melt chocolate and butter in microwave.
In a mixing bowl beat eggs with electric mixer on high until the thicken slightly. Add sugar slowly. Add vanilla and mix well. Add chocolate/butter mixture and beat on medium until uniformly brown. Add flour and blend at low speed until just combined. Do not over mix. Pour half the brownie batter into pan. Sprinkle chocolate chips evenly over the brownie batter. Add the last half of brownie batter to the top. Bake for about 40 minutes or until a toothpick inserted in center comes out clean (there will be a little chocolate on the toothpick but there should be no batter.