In a medium bowl, whisk together the flour, cocoa powder, baking soda, and salt. This will help ensure that the dry ingredients are evenly mixed and helps prevent clumping. The mixture should be a lovely deep brown color.
In the bowl of a stand-up mixer, with the paddle attachment, add the butter and sugar. Beat on medium speed until the mixture is light and fluffy, about 2 minutes. It should look pale and creamy, indicating that enough air has been incorporated.
Add the egg and vanilla to the mixture and beat until well combined. You’ll notice the mixture becoming smoother and more cohesive. Scrape down the sides of the bowl as needed.
Now, gradually add the dry ingredients from the first bowl, covering the mixer with a clean kitchen towel to avoid a flour explosion. Start the mixer on low speed and then turn it to medium. Mix until combined, about 40 seconds. The dough should look thick and chocolatey.
Gently fold in the chopped Cadbury chocolate mini eggs until evenly distributed throughout the dough. This step is crucial for ensuring every bite has that delicious chocolate surprise.
Cover the bowl with plastic wrap and transfer the cookie dough to the fridge. Allow it to chill for about 1 hour. This helps the cookies maintain their shape while baking and enhances the flavors.
Once the dough is chilled, preheat your oven to 350 degrees F. This is an important step to ensure even baking.
Line a baking sheet with parchment paper. Use a cookie scoop to scoop the dough onto the prepared sheet, spacing them about 3 inches apart. Press the tops of the cookie dough balls slightly with your hands to flatten them a bit.
Bake for 10 to 12 minutes, or until the cookies are set in the center. Watch the cookies closely; they may not appear brown, but they will be done when they’re no longer glossy on top. It’s a fine balance!
Once baked, remove the cookies from the oven and allow them to cool on a wire rack completely. While they’re still warm, sprinkle the tops with flaky salt for that perfect sweet-salty contrast.
