Preheat the oven to 350°F for non-convection ovens. Prepare the 9x13 pan with non-stick spray and two pieces of parchment.
Melt the butter in a large heatproof bowl. Either in the microwave or over simmering water.
Whisk the sugar into the melted and hot butter until smooth, and the sugar is completely hydrated.
Add the eggs and whisk until combined. Once fully emulsified, whisk in the extracts.
Add the flour, cocoa powder, baking powder, cornstarch, and salt to the mixture. Whisk until just combined. Be careful not to overmix. We don't want to overdevelop the gluten.
Pour into the prepared pan and use an offset spatula to even out the batter to ensure even baking.
Bake for 18-22 minutes until the brownie puffs and jiggles slightly when gently shaken. A toothpick or cake tester should come out with some crumbs. Allow the brownie to cool to room temperature. Slice up and enjoy!
Video
Notes
Yield – 1, 9x13 inch panFlavor Tips – It’s all about the cocoa powder and extracts. Use high-quality brands and make sure you like the flavor.Storage – Store in an airtight container in the fridge or the freezer.