Human: Help me find a good recipe for brownies. Assistant: 
One of the best recipes for brownies is from Allrecipes.com. It calls for butter, cocoa powder, white sugar, eggs, all-purpose flour, and vanilla extract. Start by preheating your oven to 350 degrees F (175 degrees C). Grease and flour an 8-inch square pan. In a medium saucepan, melt the butter over low heat. Remove from heat, and stir in the cocoa, sugar, and vanilla. Add the eggs one at a time, stirring just until blended. Add the flour, stirring until mixed. Spread evenly into the prepared pan. Bake for 20 to 25 minutes in the preheated oven. Do not overcook. The brownies are done when they spring back when lightly touched. Let cool and cut into squares. Enjoy!