TO MAKE THE BROWNIES:
Preheat the oven to 350°F (175°C). Grease a 9"x9" pan and line with parchment paper.
In a large bowl, stir together the flour, baking powder, cocoa powder, granulated sugar, and brown sugar.
In a separate bowl, whisk together the eggs, milk, and melted butter. Pour the wet mixture into the bowl with the dry mixture, and stir until fully combined. Fold in the chocolate chips and stir again.
Transfer the batter to the prepared pan, and spread evenly. Bake for 25-30 minutes, or until the brownies are almost set but the center wobbles slightly. Remove from the oven and let the brownies cool in the pan on a wire rack.
TO MAKE THE MERINGUE:
Place the egg whites, lemon juice, and sugar in a heatproof bowl (preferably stainless steel or glass).
Put the bowl over a saucepan with simmering water. The bowl should fit snugly, and the simmering water should not be touching the bowl. Whisk constantly, until the sugar has melted and the mixture is hot to touch. (The meringue should reach 160°F (71°C).) Then, remove the bowl from the heat.
With an electric or stand mixer beat 5-6 minutes, until white and fluffy.
Fold in the chocolate chips and stir gently.
Frost the brownies with the meringue and serve.
