Preheat oven to 350 °F (175 °C). Grease an 8 × 8‑inch baking pan or line it with parchment.

In a bowl, combine the red velvet cake mix, egg, vegetable oil, vanilla, and water. Mix until thick and sticky.

Fold in the semi‑sweet chocolate chips.

Spread the batter evenly into the prepared pan.

Bake for about 20 minutes, until the edges are set but the center remains soft and fudgy.

Allow the brownies to cool completely in the pan on a wire rack.

Prepare the frosting:

If using ready‑made, simply frost once brownies are cool.

If making homemade, beat the room‑temperature cream cheese and butter until smooth. Add powdered sugar, vanilla, and milk; mix until light and creamy.

Frost the cooled brownies. For a pretty swirl effect, pipe the frosting using a plastic bag with a cut corner and lightly swirl.

Slice into squares—wipe the knife clean between cuts for neat edges.