2-Ingredient Brownies - Secretsfrommyapron

1 2/3 cups semi-sweet chocolate chips (about 12 ounces)

4 large eggs

Preheat the oven to 350 degrees F. Line an 8-by-8-inch square baking pan with parchment, leaving a 2-inch overhang on 2 opposite sides.
Place 1 1/3 cups of the chocolate chips in a medium microwave-safe bowl. Microwave the chocolate until melted, stirring halfway through, about 2 minutes. Let cool slightly, about 5 minutes.
Separate the egg whites into a large bowl. Add the yolks and 2 tablespoons water to the chocolate, then whisk until smooth and combined; set aside, Whip the egg whites with an electric mixer on medium-high speed until stiff peaks form. Gently fold 1/3 of the chocolate mixture into the egg whites, mixing until just combined (you want the whites to stay as fluffy as possible). Repeat 2 more times with the remaining chocolate, folding until well combined.
Pour the batter into the prepared pan and bake until the brownies are set and a toothpick inserted into the center comes out clean, 25 to 27 minutes. Sprinkle the remaining 1/3 cup chocolate chips over the top and return to the oven; bake until just beginning to melt, about 2 minutes. Remove from oven and spread the melted chocolate all over the top of the brownies with an offset spatula.
Let cool completely in the pan, about 30 minutes, Use the parchment overhang to remove the brownies from the pan and cut into squares.