First, I softened my butter and mixed it with both brown and granulated sugars until smooth and fluffy. It took about a minute on medium speed, and the texture looked perfect for a rich, tender cookie base.
Next, I beat in the egg and vanilla until fully combined. This step ensures the dough binds properly and gives a lovely soft texture once baked.
In another bowl, I whisked together flour, cocoa powder, baking soda, espresso powder, and salt. This step makes sure the chocolate flavor is even throughout the cookie.
I added the dry mixture into the butter mixture, blending on medium-low just until combined. Overmixing here can make the cookies tough, so I kept it brief.
Then I gently folded in the mini eggs (half chopped, half whole) and dark chocolate pieces. The dough was sticky but studded beautifully with colorful chocolate.
I covered the dough with plastic wrap and chilled it for 30–45 minutes. Chilling helps control spreading and makes the cookies fudgy yet structured.
While the dough chilled, I preheated the oven to 350°F (175°C) and lined a baking sheet with parchment paper. This prevents sticking and ensures even baking.
Using an ice cream scoop, I portioned the dough into balls and placed them on the lined sheet. I topped each with a pinch of flaked sea salt, which adds a perfect flavor contrast.
Finally, I baked the cookies for 10–12 minutes. After baking, I let them rest on the sheet for 15 minutes before moving them to a cooling rack to set completely.