Preheat the oven to 350°F. Line 2 baking sheets with parchment paper and set aside.
In a large bowl, cream together the butter and sugars until light and fluffy. Mix in the egg and vanilla until fully incorporated.
In a separate bowl, mix together the flour, corn starch, baking soda and salt. Mix the dry ingredients into the wet ingredients until fully combined. Fold in the mini eggs.
Using a cookie scoop, scoop the dough onto the prepared baking sheets and bake in the preheated oven for 8-10 minutes, or until lightly brown. Allow to cool completely on the baking sheet.