Preheat the oven to 425° F and spray a baking sheet with nonstick cooking spray.
In a medium bowl. combine the cornbread mix with the self-rising flour and garlic powder. Cut the butter into the mixture with a pastry blender or two butter knives until the butter is cut into pieces the size of peas. Add the jalapeños and cheddar cheese. Pour in the milk and stir to combine. Drop in half-cup measurements onto the baking sheet leaving about 3 inches of space between each biscuit. Bake for 18 to 20 minutes, or until golden browns and cooked through. Serve warm.
