In a mixing bowl, mix melted (but cooled) butter, 2 eggs, 1/4 cup milk, 2 tsp vanilla.
Combine dry ingredients (sifted if you're an overachiever--I'm not!) in a bowl. Then mix dry with wet just until smooth batter is formed. (Truth is, I add the dry ingredients right on top, then stir a little with a spoon right on top to combine before mixing it all together. One less bowl.)
Spread batter in a parchment lined or sprayed 9x13 pan and sprinkle with 1 cup of chocolate chips. Bake at 350 for about 25 minutes.
I often double this recipe, and bake in a large parchment-lined sheet pan for 35-40 minutes.
You can use milk or semi sweet chips, or even chopped chocolate bars etc... I usually prefer semi-sweet chips.
I've even made these when I was supposed to bring a pink treat for a baby shower. Skipped the chocolate chips and cut them into tiny squares topped with fresh raspberry buttercream. CROWD pleaser.
Recipe is calculated for 20 brownies (4x5) cut out of a 9x13 pan.