Step 1

Preheat your oven to 325°F. Line an 8-inch square cast aluminum baking pan with parchment paper or nonstick aluminum foil (or line with regular aluminum foil and spray with nonstick cooking spray). Set the pan aside.

Step 2

In a small saucepan, place the butter and sugar, and place over medium heat, whisking occasionally, until melted and simmering. Remove the saucepan from the heat and set it aside to cool until no longer hot to the touch.

Step 3

Alternatively, cool the butter and sugar mixture down a bit by placing the bottom of the saucepan in a bowl of cool water. Make sure the butter does not solidify.

Step 4

In a large bowl, place the eggs and vanilla, and whisk until well-beaten and combined.

Step 5

Add the melted and cooled butter and sugar to the bowl slowly, whisking constantly. Add the cocoa powder and whisk until the cocoa powder has been absorbed.

Step 6

Using a handheld mixer, beat until very well-combined.

Step 7

Add the flour, xanthan gum, cornstarch, baking soda, and salt, and mix with a silicone spatula or spoon until just combined.

Step 8

Add about 4 ounces of the chocolate chips and mix until just evenly distributed throughout the batter. The batter will be thick and sticky.

Step 9

Transfer the brownie batter to the prepared pan and, using an offset or silicone spatula, spread into an even layer. It helps to moisten the tool you are using to smooth the top a bit to prevent it from sticking.

Step 10

Scatter the remaining chocolate chips evenly over the top of the brownie batter and bang the pan firmly on the countertop to help the chips adhere.

Step 11

Place the pan in the center of the preheated oven. Bake just until the brownies are no longer wet in the center, about 28 minutes.

Step 12

The center may dome during baking, but the brownies will settle as they cool.

Step 13

Remove the brownies from the oven and allow them to cool in the pan at room temperature until the pan is no longer hot to the touch.

Step 14

For clean lines when you slice the brownies, place the brownies, still in the pan, in the refrigerator to chill for about an hour before slicing them.

Step 15

When you're ready to slice the brownies, remove them from the pan and peel away the foil. Slice the brownies into 9 or 12 equal rectangles or squares.

Step 16

Serve the brownies immediately, or wrap tightly and freeze for longer storage. These freeze incredibly well.