Preheat your oven to 325F and line baking sheets with parchment paper.
In a medium saucepan, melt the butter over medium heat. Continue to cook, stirring and swirling the pan occasionally, until the butter turns golden brown and has a nutty aroma. Remove from heat and let cool to room temperature in a separate bowl.
½ cup unsalted butter
To the brown butter add in the brown sugar and granulated sugar and whisk until well combined. Add the egg and vanilla extract, and whisk until smooth.
½ cup brown sugar, ¼ cup granulated sugar, 1 large egg, 1 tablespoon vanilla extract
In a separate bowl, whisk together the flour, baking soda, and salt. Add dry ingredients to the wet ingredients, mixing until just combined.
1 & ¼ cups all-purpose flour, ½ teaspoon baking soda, ½ teaspoon salt
Fold in the chocolate chips and chopped Cadbury mini eggs.
½ cup mini chocolate chips, ¾ cup chopped Cadbury mini eggs
Using a large cookie scoop or spoon, drop rounded balls of dough onto the prepared baking sheets.
Bake in the preheated oven for 13 minutes, or until the edges are set and the centers are still slightly soft.
Remove from the oven and let cool on the baking sheets for 5 minutes, then transfer to a wire rack to cool completely.