1. In a stand mixer (preferred) cream together 1 1/2 cups cubed butter and sugar until light and fluffy. About 5 mins. If clumping together, scrape the mixture with a spatula off the sides and the whisk to ensure a smooth mixture. (you may need to do this a few times)

2. While that is blending, melt the chocolate with the remaining butter. Bring a small saucepan filled half way with water to a boil. Once boiling, reduce to simmer and place a large heat safe bowl overtop to create a bain marie. Add the butter and chocolate to the bowl and stir until just melted. Remove from heat and let chill 2 minutes.

2. To the stand mixer, add eggs one at a time, mixing well after each addition. Add the cocoa powder and vanilla and continue to mix until just incorporated.

3. In a separate bowl sift together the flour, cornstarch, baking soda, and salt. Slowly incorporate the dry ingredients into the cocoa mixture, alternating with the melted chocolate. Mix until just combined. Use a cookie scoop to form 2 inch balls and place on a baking sheet lined with parchment. Chill the cookie balls for 30 minutes in the freezer.

4. Preheat the oven to 325 degrees F. Line a cookie sheet with parchment paper and place cookie balls leaving space in between each dough and bake 1 sheet at a time for 10 minutes until the edges just begin to crisp. Remove from the oven and gently press halved mini eggs into the cookies. Return to the oven and cook an additional 2 minutes. The cookies should look soft and fluffy. Allow to rest on tray for 2 minutes before transferring to cooling rack. Repeat until all the cookies are baked.

5. Enjoy warm.