Preheat the oven to 350 degrees F (175 degrees C). Line a muffin pan with paper or foil liners.

Sift together flour, cocoa, baking powder, baking soda, and salt.

Cream together sugar and butter in a large bowl until light and fluffy.

Add eggs, one at a time, beating well after each addition. Stir in the vanilla. Add flour mixture in two batches, alternating with milk; beat well.

Spoon batter into the prepared muffin cups, filling each 3/4 full.

Bake in the preheated oven until a toothpick inserted into the centers comes out clean, 15 to 17 minutes. Remove from the oven and let cool before serving or frosting.