Place the butter, granulated sugar and brown sugar in the bowl of an electric mixer. Beat for 2-3 minutes or until the butter and sugar is light and fluffy.
Add the eggs and vanilla extract to the bowl. Beat until thoroughly combined.
In a medium bowl, mix together the flour, corn starch, baking soda, baking powder and kosher salt. Add half the dry mixture to the mixing bowl and mix on low speed to combine.
Add the remaining dry ingredients and mix on low speed until just blended. Fold in the semisweet chocolate chips and chopped mini eggs.
Scoop out 2 tablespoons of dough and roll it into a ball. Repeat the process with the remaining dough.
Place the cookies 2 inches apart on two sheet pans lined with parchment paper or silicone baking mats. Freeze for 10-15 minutes or until firm.
Preheat the oven to 350 degrees F.
Bake one sheet of cookies at a time for 10-12 minutes or until edges are lightly browned. Immediately press the whole mini eggs into the tops of the cookies when they come out of the oven.
Let the cookies rest on the pan for 3-5 minutes, then transfer to a cooling rack. Serve when cool, or store in an airtight container for up to 5 days.
Notes
Scoop your cookie dough with a measuring spoon or cookie dough scoop to make sure you end up with cookies that are all the same size.
I prefer to use Cadbury mini eggs, but any candy coated chocolate eggs brand will work.