1
Stir together the melted butter, sugars, eggs, and vanilla extract.
2
Sift in the flour and cocoa. Add the salt and espresso powder, if using, and stir.
3
Fold in the chopped chocolate and chopped Oreos.
4
Spread in a prepared pan and place chopped Oreos on top. Bake and sprinkle with flaky sea salt, if desired. Let cool before cutting into squares.