Prepare a 8"x8" pan with parchment paper. I like to lighly spray or drip oil into the pan and use that to keep the parchment paper stuck to the bottom and sides of the pan.
In a large bowl, add 1¼ semi-sweet chocolate chips and ½ cup butter (1 stick). Microwave in 30 second increments until butter is melted. Stir thoroughly between each blast in the microwave until the chocolate is melted and smooth.
Add ⅓ cup sugar and 1 tsp salt and mix together until combined.
Stir in the sugar and salt should help cool the chocolate, but double check before adding the eggs (otherwise they might scramble). I just check by dipping in a finger and if it's warm but not hot, it should be fine. Add 2 eggs and mix until combined.
Add 1 cup flour and mix until combined.
Add batter to the prepared 8"x8" pan and bake at 325°F for 15-20 minutes or until the edges just barely begin to brown and the center no longer jiggles when you shake the pan. Allow to cool.