Preheat oven to 350 F.
Coat a 9x13 baking dish with cooking spray.
In a large bowl, combine the melted butter, sugar, vanilla, and coffee. Beat in the eggs one at a time.
In a medium bowl, sift the flour, cocoa powder, and salt. Stir the flour mixture into the sugar mixture until just blended. Stir in the chocolate chips.
Spread the batter evenly in the pan. Bake 35-40 minutes or until a toothpick inserted in the center comes out clean. Cool before cutting.