Ingredients
Method
- Preheat oven to 350°F (175°C). Generously grease a 12-cup standard muffin tin with non-stick cooking spray.
- In a large mixing bowl, whisk together the melted butter, brown sugar, and granulated sugar vigorously until smooth and glossy (about 1 minute).
- Whisk in the egg, egg yolk, and vanilla extract until fully combined.
- Add the flour, cornstarch, baking soda, and salt. Use a rubber spatula to mix just until no flour streaks remain. Fold in the chocolate chips.
- Divide the dough into 12 even balls (approx 2 tbsp each). Place one ball into each muffin slot. Use your thumb or a small shot glass to press a deep indentation into the center of the dough, pushing the dough up the sides slightly.
- Bake for 10-12 minutes. The edges should be golden brown, but the center may look slightly soft. Do not overbake.
- Remove from oven. Immediately press the centers down again with the back of a spoon or a shot glass to redefine the cup shape.
- While still hot, spoon about 1-2 teaspoons of chocolate hazelnut spread (or ganache) into the center of each cup. Top with extra chocolate chips if desired.
- Allow the cups to cool in the pan for at least 15 minutes to set before gently removing them with a butter knife.
Notes
Storage: Keep in an airtight container for 3 days. Microwave for 10 seconds to restore the gooey center.
