Ingredients
Equipment
Method
Preheat and prep pan
- Preheat the oven to 425F, then line a 12-cup muffin tin. Make sure the liners are seated so the batter can dome high.
Mix dry ingredients
- Whisk the all-purpose flour, cocoa powder, baking powder, baking soda, espresso powder, and salt until evenly combined. The mixture should look uniformly dark with no pale flour streaks.
Mix wet ingredients
- Whisk the granulated sugar and brown sugar with the eggs, buttermilk, vegetable oil, cooled coffee, and vanilla until smooth. Stop when the sugar is fully dispersed and the batter looks glossy.
Combine and fold in chocolate
- Fold the dry mixture into the wet mixture until just combined, then fold in the dark chocolate chips. Keep mixing minimal so the muffins stay tender rather than tough.
Fill and top
- Fill each muffin cup to the very top, then sprinkle espresso powder over each. The near-full fill is what supports tall, domed tops.
Bake with a two-step temperature
- Bake at 425F for 5 minutes, until the tops rise noticeably and look set around the edges. This high initial heat drives the tall domed shape.
- Reduce the oven to 350F and bake 13-15 more minutes until a toothpick comes out mostly clean with a few moist crumbs. Cool briefly before removing from the pan to avoid breaking the domes.
Notes
For best domes, don’t overmix after adding the dry ingredients—stop as soon as you see no dry flour. Store airtight at room temperature up to 2 days or refrigerate up to 4 days; freeze baked muffins up to 2 months. For a reduced-sugar option, replace the brown sugar and granulated sugar with an equal-measure sugar substitute labeled for baking (texture may be slightly less fudgy).