Preheat oven to 350 degrees
In a heavy-duty sauce pan or microwaveable bowl, melt 1 cup of the chocolate chips and the butter over low heat, stirring frequently until chips are completely melted. If you're using the microwave method, heat chips in short increments, (according to package directions) and stir in between.
Remove from heat, allow to cool slightly, and stir in the vanilla extract, then the eggs, one at a time.
Add the sugar, flour, baking soda and cinnamon. Stir until completely blended.
Stir in the remaining chocolate chips
Spread brownie batter into a greased or parchment paper-lined 13 X 9-inch baking pan, and bake at 350 degrees for about 20 to 25 minutes, or until the edges are firm, center is set, and a toothpick comes out mostly clean. Do not over bake -- center will firm up as brownies cool
Allow to cool, slice, and enjoy!