Preheat air fryer to 325°. Line a 6-in. square or round cake pan with parchment, letting ends extend up sides. In a small microwave-safe bowl, melt butter and 1 cup chocolate chips; stir until smooth. Cool slightly. In a small bowl, beat sugar and eggs. Stir in water and vanilla. Combine flour, baking soda and salt; gradually add to chocolate mixture. Fold in remaining 1/2 cup chocolate chips.
Pour into prepared pan. Bake until a toothpick inserted in center comes out with moist crumbs, 40-45 minutes (do not overbake). Tent with foil as needed to prevent overbrowning. Cool on a wire rack.
Lifting with parchment, remove brownies from pan. Cut into squares.
Air-Fryer Brownies Tips
What other pans can you use to make air-fryer brownies?
You can also make air-fryer brownies in 8- or 10-oz ramekins, baking for about 20 minutes. These will typically have a more gooey center than a full pan, but check for doneness the same way you would for other brownies. Make any kind of brownies test better with these brownie tips from our Test Kitchen.
Even if you’re not trying to make mocha brownies, a touch of instant espresso powder or coffee can give you a deeper chocolate flavor. Also consider adding chopped toasted walnuts, flavored baking chips, or caramel bits to make these brownies your own.