Preheat your oven to 350°F. Prepare an 8x8 inch baking pan by lining it with parchment paper or spraying it with a gluten-free non-stick cooking spray.
For the wet ingredients, whisk together melted butter, granulated sugar, brown sugar, and vanilla extract in a large bowl until well combined. Add eggs one at a time.
For the dry ingredients, sift together the gluten-free flour, cocoa powder, baking soda, and salt in a separate bowl.
Gradually mix the dry ingredients into the wet ingredients until just combined and smooth.
Pour the batter into the prepared baking pan, smoothing the top with a spatula.
Bake in the preheated oven for 30 minutes if you like them gooey or a few minutes more if you like them set. Allow the brownies to cool in the pan on a wire rack before cutting into squares.