01 - Preheat the oven to 350°F. Lightly grease two 4-inch ramekins or mini cake pans with butter or cooking spray.
02 - In a small bowl, whisk together the flour, cocoa powder, baking powder, salt, and sugar until evenly distributed.
03 - In a separate bowl, whisk the egg, milk, melted butter, and vanilla extract until smooth and fully incorporated.
04 - Pour the wet ingredients into the dry ingredients. Stir gently with a spatula until just combined. The batter should remain slightly lumpy—do not overmix.
05 - Gently fold in the semi-sweet chocolate chips if using, distributing them evenly throughout the batter.
06 - Divide the batter evenly between the two prepared ramekins, smoothing the tops with a spatula.
07 - Bake for 16-18 minutes, or until a toothpick inserted into the center comes out with a few moist crumbs attached.
08 - Let the cakes cool in the ramekins for 5 minutes before unmolding. Dust with powdered sugar or serve warm with berries, whipped cream, or ice cream.