Preheat oven to 350F. Grease and line an 8 x 8” baking pan with parchment paper.
In a large microwave safe bowl, combine butter and sugar. Do it in 30 second intervals and stir gradually with a whisk until the mixture has a glossy finish.
Allow the mixture to cool, then add your eggs in one at a time. Whisk between each addition
Add in cocoa powder, salt and vanilla extract. Fold in flour until just combined.
Pour the mixture into prepared baking pan and bake for about 25-30 minutes until they are set. The center will be gooey so remove from oven and let them cool completely. It can take up to 35 minutes to bake depending on your oven!
