Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.

In a medium bowl, whisk together the all-purpose flour, baking soda, cornstarch, and salt.

In a large bowl, mix melted butter with granulated sugar and brown sugar until smooth. Add egg and vanilla extract, mixing until creamy.

Gradually combine the dry mixture with the wet ingredients, taking care not to overmix. Fold in chocolate chips and crushed mini eggs.

Using a large cookie scoop, portion out the dough onto the baking sheet, spacing them at least 2 inches apart.

Bake in preheated oven for about 11 minutes until the edges are light golden brown.

Allow cookies to cool on the baking sheet for 5 to 10 minutes before transferring to a cooling rack.