Preheat & Prepare: Preheat the oven to 350°F and line a baking sheet with parchment paper.
Cream the Butter & Sugar: In a stand mixer, beat the softened butter, brown sugar, and granulated sugar until light and creamy.
Add Wet Ingredients: Mix in the egg and vanilla extract until smooth.
Combine Dry Ingredients: Gradually mix in the flour (about ½ cup at a time) on low speed until fully incorporated. Stir in baking soda, salt, and oats until evenly distributed.
Fold in the Chocolate & Cadbury Eggs: Gently fold in the chocolate chips and 1 cup of the crushed Cadbury mini eggs.
Shape the Cookies: Scoop out dough using a 3-tablespoon cookie scoop and place each ball 3 inches apart on the prepared baking sheet.
Bake to Perfection: Bake for 8-9 minutes, or until the edges turn a light golden brown.
Add Extra Festive Touch: Immediately press the remaining crushed Cadbury mini eggs on top of the warm cookies.
Cool & Enjoy: Let the cookies cool on the pan for about 10 minutes before serving. Enjoy with a cold glass of milk!