Add the butter to a saucepan over medium heat. Stir constantly as the butter melts and begins to foam. Continue cooking until the butter turns golden and you see small brown specks forming on the bottom of the pan. It should smell nutty and rich.
Remove from heat immediately and pour into a bowl to stop the cooking. Let cool for about 20 minutes, until warm but not hot.
Prep the Cadbury eggs:
Place the Cadbury Mini Eggs in a zip-top bag and crush them using a meat tenderizer or rolling pin. Aim for chunky pieces.
Set aside a small handful of the crushed eggs to use for topping the cookies later.
Making the dough:
In a bowl whisk together: flour, baking soda, baking powder, and salt.
In a separate bowl whisk together the browned butter, brown sugar, and granulated sugar until smooth and glossy.
Add the eggs and vanilla and mix until combined.
Stir in the dry ingredients until just incorporated.
Fold in the crushed Cadbury Mini Eggs.
Do I need to chill the dough?
You can bake these cookies right away, no chilling required. Because the butter is browned and cooled before mixing, the dough holds its shape well and bakes into thick, soft cookies. If your kitchen is warm or you want slightly thicker cookies, you can chill the dough for 20–30 minutes, but it is not necessary.
Baking the cookies:
Preheat oven to 350°F.
Scoop dough into balls (about 2 1/2 tablespoons each) and place on a parchment-lined baking sheet.
Press a few of the reserved Cadbury egg pieces onto the tops of each cookie so the colorful shells show after baking.
Bake for 9–10 minutes, until the edges are set but the centers are still soft.
Let the cookies cool on the baking sheet for 5 minutes before transferring to a cooling rack.
Notes
Nutrition information is estimated and may vary depending on ingredient brands and portion sizes.