Step 1

Preheat oven to 350º F and lightly grease a 9x13-inch baking dish with butter or non-stick spray.

Step 2

Mix cake mix with 1/2 cup (1 stick) melted butter, 1 egg and 1 teaspoon vanilla extract in a large bowl until just combined, then transfer to greased baking dish. Use a rubber spatula to spread mixture into an even layer.

Step 3

In a separate bowl or mixer, beat cream cheese for 2-3 minutes, or until smooth, then add eggs one at a time, waiting for each to be incorporated before adding the next. Mix in cocoa powder and instant coffee granules until smooth.

Step 4

Gradually mix in powdered sugar (on low speed, if using a mixer), then drizzle in remaining melted butter and vanilla extract.

Step 5

If using, fold in chocolate chips until just combined.

Step 6

Pour mixture over batter in the baking dish and gently spread it into an even layer.

Step 7

Place baking dish in oven and bake for 45-50 minutes, or until edges are pulling away from the sides of baking dish and the center is just set.

Step 8

Remove from oven and let cool at least 40 minutes, or until set.

Step 9

Slice, serve and enjoy!