Preheat oven to 350°F (176°C) and line a 9" x 9" baking dish with parchment paper.
Melt the butter in a small saucepan over low heat. Add the chocolate chips, vanilla extract and dutched cocoa powder. Stir the ingredients until the chocolate chips have melted and the mixture is smooth. Remove the saucepan from the burner and set it aside to cool down.
In a large mixing bowl, beat the eggs, brown sugar and granulated sugar with an electric mixer for 7-10 minutes. Add the sourdough discard and chocolate mixture to the bowl beat on low until combined. Add the flour and salt and stir with a spatula until just combined. (The batter will be very thick.)
Pour the batter into the baking dish and smooth the top. Bake for 35-40 minutes.
Allow the brownies to cool completely in the pan after they come out of the oven. Remove the brownies from the pan by lifting them with the parchment paper and cut into squares.