Fudgy Brownie Muffins: One-Bowl, Quick, and Irresistible Step-by-step instructions

Before you start

Before starting, measure all ingredients and bring the eggs to room temperature if possible—cold eggs take longer to whip. Line a 12-cup muffin tin with paper liners. Set up a double boiler by filling a saucepan with an inch of water and bringing it to a gentle simmer.

Have your electric hand mixer or whisk ready. Preheat the oven to 350°F (175°C) about 10 minutes before you plan to bake. You'll also want a wire cooling rack ready for when the muffins come out.

Instructions

Melt and Whisk

1. 1Melt Chocolate and Butter
   Fill a medium saucepan with 1 inch of water and bring to a simmer over medium heat. Place a heatproof bowl on top, making sure the bottom doesn't touch the water. Add the chopped chocolate and butter to the bowl. Stir occasionally with a silicone spatula until completely melted and smooth. Remove the bowl from the heat and set aside to cool slightly while you prepare the eggs.
   Look for The chocolate and butter should be glossy and fully combined, with no lumps.
   Tip Make sure no water gets into the chocolate or it will seize. Use a dry bowl.
2. 2Whisk Eggs and Sugar
   In a large mixing bowl, combine the eggs and granulated sugar. Using an electric hand mixer or a whisk, beat on high speed for 2 to 3 minutes until the mixture is pale, thick, and doubled in volume. The batter should fall in a thick ribbon when the whisk is lifted. Add the vanilla extract and beat briefly to combine.
   Look for The egg-sugar mixture should be pale ivory, thick, and hold a ribbon shape for a few seconds.
   Tip Whisking thoroughly creates the crackly top. Don't rush this step.

At the end of this phase, the chocolate-butter mixture should be smooth and glossy, with no lumps.

The egg-sugar mixture should be pale ivory, thick, and doubled in volume—when you lift the whisk, the batter should fall in a thick ribbon that holds its shape for a few seconds. The vanilla should be fully incorporated. The kitchen will smell of rich chocolate and vanilla.

Fold and Scoop

3. 3Fold in Chocolate Mixture
   Pour the melted chocolate and butter into the egg-sugar mixture. Use a silicone spatula to fold gently, scraping from the bottom up, until just combined. The batter will be thick and glossy. Avoid overmixing to keep the muffins tender.
   Look for The batter should be uniform in color with no streaks of egg or chocolate.
   Tip Fold slowly and stop as soon as the chocolate is incorporated.
4. 4Add Dry Ingredients
   Sprinkle the all-purpose flour, cocoa powder, and salt over the batter. Fold again with the spatula until no dry streaks remain. The batter will be thick and slightly stiff. Let it rest for 5 minutes while the oven heats.
   Look for The batter should be smooth and thick, with no visible flour pockets.
   Tip Resting the batter helps the tops crackle during baking.
5. 5Scoop into Muffin Cups
   Line a 12-cup muffin tin with paper liners. Using a cookie scoop or two spoons, divide the batter evenly among the cups, filling each about three-quarters full. Smooth the tops slightly with the back of a spoon if needed.
   Look for The batter should be evenly distributed, with no cup overfilled.
   Tip For even muffins, use a spring-loaded scoop.

The batter should be thick, glossy, and uniform in color, with no streaks of egg or chocolate. After resting, it will be slightly stiffer. When scooped into the muffin cups, the batter should fill each about three-quarters full. The tops can be smooth or slightly mounded—either is fine. The batter should look fudgy and inviting.

Bake and Reveal

6. 6Bake Until Crackly
   Place the muffin tin in the oven and bake at 350°F (175°C) for 18 to 20 minutes, until the tops are shiny and crackly and a toothpick inserted into the center comes out with a few moist crumbs. The centers should be just set but still fudgy.
   Look for The tops will be glossy and cracked, and the kitchen will smell of chocolate.
   Safe temperature 160°F (71°C) internal temperature (egg dishes)
   Tip Start checking at 18 minutes to avoid overbaking.
7. 7Cool Slightly and Serve
   Remove the muffin tin from the oven and let it cool on a wire rack for 5 minutes. While still warm, gently break a muffin in half to reveal the fudgy center. Serve warm for the best oozing effect, or let cool completely for a firmer texture.
   Look for The center should be moist and fudgy, not dry.
   Tip Warm muffins are the most indulgent—serve within 15 minutes of baking.

The muffins should have shiny, cracked tops and be puffed up. A toothpick inserted into the center should come out with a few moist crumbs. The centers will be just set but still fudgy. When you break one open, the center should be glossy and molten. Let them cool for 5 minutes before serving—they'll be warm and incredibly gooey.

Common mistakes

One common mistake is overmixing the batter after adding the flour, which makes the muffins tough and dense. Mix just until no dry streaks remain. Another is under-whisking the eggs and sugar—if the mixture isn't pale and thick, the tops won't crackle properly.

Also, be careful not to overbake; the muffins should be moist and fudgy, not dry. Finally, don't skip the rest time before baking—it's key for the crackly top. If your muffins stick to the liners, make sure you're using good-quality paper liners or grease the tin well.

How to tell it’s done

The muffins are done when the tops are shiny, cracked, and set to the touch, and a toothpick inserted into the center comes out with a few moist crumbs clinging to it. The internal temperature should reach at least 160°F (71°C) to ensure the eggs are fully cooked.

If the toothpick comes out wet with batter, bake for another 2 minutes and check again. The centers should be just set but still fudgy—they will continue to set as they cool. Overbaking will dry them out, so err on the side of slightly underdone for a gooey center.

• Egg dishes: 160°F (71°C) in the thickest part