Preheat oven to 350°F and prepare baking sheets with parchment paper.
Beat softened butter, brown sugar, and granulated sugar for 2–3 minutes until light and fluffy.
Add eggs one at a time, then mix in vanilla extract until combined.
Whisk flour, baking soda, and salt in a separate bowl.
Add dry ingredients gradually and mix until a soft dough forms.
Fold Easter M&M candies into the dough, saving a few for topping.
Scoop dough portions of about 2 tablespoons and chill for 15 minutes.
Bake cookies for 10–12 minutes until edges are lightly golden and centers remain soft.
Cool on the baking sheet for 5 minutes, then transfer to a rack.