Super Chocolatey Extra Small Batch Brownies

Bahan-bahan (4 porsi)

• 1 ounce dark chocolate (chopped)
• 2 tbsp butter
• 1/2 tsp cocoa powder
• 2 tbsp tightly packed brown sugar
• 2 tbsp white sugar
• 1/2 large egg (see notes)
• 1/4 tsp vanilla
• 2 tbsp all purpose flour
• tiny pinch of salt