Preheat your oven to 375°F. Grease an 8x8-inch baking pan or line it with parchment paper.
In a large bowl, combine the Krusteaz Cornbread Mix, vegetable oil (or melted butter), milk, and egg. Stir until just combined. Do not overmix; a few lumps are okay.
1 box Krusteaz Honey Cornbread & Muffin Mix, 1/3 cup vegetable oil or melted butter, 1 cup milk, 1 large egg
If desired, fold in optional add-ins such as corn kernels, shredded cheddar cheese, or chopped jalapeño. You can use a mix of these as well. I went with cheddar and corn.
1/2 cup corn kernels, 1 cup shredded cheddar cheese, 1/2 jalapeño
Pour the batter into the prepared baking pan and spread it evenly.
Bake in the preheated oven for 20-25 minutes or until the top is golden brown and a toothpick inserted into the center comes out clean.
Allow the cornbread to cool in the pan for a few minutes before transferring it to a wire rack to cool completely. Cut into squares and serve.