Preheat oven to 400°F. Lightly grease an 8x8 baking pan and set aside.
In a medium bowl, add milk, water and egg and mix to combine. Add cornbread mix and mix with a fork until moistened. Do not over-mix.
Pour into the prepared baking dish and bake for 23-36 minutes
Let cornbread cool and cut into ¾” x ¾” cubes.
Preheat oven to 350 degrees.
Add cornbread cubes into a large bowl and lightly toss with olive oil and garlic salt. Pour onto a parchment paper lined baking sheet.**
Bake for 15 minutes, then toss cubes and bake for an additional 10-15 minutes. They should be mostly hard to the touch and will continue to harden once removed from oven.
Let cool and then store or add to your favorite salad.
**If time allows, place on a parchment paper lined baking sheet and let sit overnight, uncovered, to become more stale. If you do not have time for this, you will just need to bake the cubes 5 minutes longer.