In a large mixing bowl, beat brown sugar, sugar, and butter until fluffy.

Add egg, milk, vanilla, and red food color, beating until combined.

In a medium bowl, whisk together flour, cocoa powder, baking soda, and salt.

Add to mixing bowl gradually, beating until combined.

Fold in mini chips and chocolate chunks.

Spray a 10-inch cast-iron skillet with non-stick spray.

Spread the batter evenly into the skillet.

Bake at 325 for 40-45 minutes, or until edges are golden and a toothpick inserted near the center comes out with a few moist crumbs, but mostly clean.

Cool for 15 minutes. Cut into slices.

Serve warm with ice cream and chocolate sauce.