Preheat the oven to 350°F (175°C). In a mixing bowl, combine brownie mix, water, and egg. Mix until smooth and set aside.

In another bowl, cream together the softened butter, granulated sugar, and brown sugar until light and fluffy.

Add the egg and vanilla extract, mixing until well combined.

In a separate bowl, whisk together the flour, baking soda, and salt. Gradually add to the wet ingredients, mixing until just combined.

Fold in the chocolate chips.

Scoop a tablespoon of cookie dough and flatten it in your palm. Place a small spoonful of brownie filling in the center, then wrap the cookie dough around the filling and roll into a ball.

Place the cookie balls on a baking sheet lined with parchment paper, spacing them about 2 inches apart.

Bake in the preheated oven for 12-15 minutes, or until the edges are golden brown. The centers may look slightly underbaked, but they will set as they cool.

Remove from the oven and let cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.