Preheat oven to 350°F (180°C).

Lightly grease an 8" x 8" (2L) metal pan and line with parchment paper.

Melt the chopped chocolate with the butter either in the microwave or in the top of a double boiler. Cool to lukewarm.

In a large bowl, beat the eggs with the sugar until thick and fluffy, about 4 minutes. Add the vanilla and beat to combine. Mix in the chocolate mixture. Fold in the flour and salt to blend.

Add the chocolate chips and pour into the prepared baking dish.

Bake for 25-27 minutes or until set. It will start to crackle on top. Cool on a baking rack before cutting.

Variation: If you prefer a denser brownie, do not beat eggs and sugar for as long.