Brownie recipe:
4 eggs
1 1/4 cups unsweetened cocoa powder
1 teaspoon salt
1 teaspoon baking powder
1 Tablespoon (3 teaspoons) vanilla extract

 
1 cup (2 sticks) butter
2 1/4 cups sugar
1 1/2 cups all purpose flour 
about 11 Oreos, chopped

Directions:

Preheat oven to 350 and line 9″x13″ pan with nonstick foil.
In a large bowl, add 4 eggs, and beat with cocoa, salt, baking
powder, and vanilla. Stir until fully combined and
smooth.
In the microwave, melt butter. When melted, add sugar, and stir to
combine.
Add warm butter/sugar mixture to the egg/cocoa mixture, stiring until
smooth.
Add the flour to batter and stir until fully incorporated.
Stir in Oreos.  Spread batter into prepared pan, and smooth as needed.
Bake brownies about 30 minutes. Test for doneness by inserting a
toothpick.  You should find moist crumbs.
Cool and cut into small bite sized squares. Adapted from King Arthur Flour