Preheat the oven to 325°. Grease an 8x8 pan with butter & parchment. Roughly chop the entire bag of mini eggs. NOTE: smashing the eggs with the flat side of a knife (like you would a clove of garlic) is easiest.

In a medium bowl, add 2 eggs and 1 egg yolk, brown and white sugar. Whisk together until combined. In a microwave safe bowl, melt butter & semi-sweet chocolate in 30 second increments. Stir to combine and pour the chocolate butter mixture into the eggs and sugar. Whisk until combined. Add vanilla extract & stir.

In a large bowl, add flour, cocoa powder & salt. Whisk until combined.

Add dry ingredients to wet & whisk until combined. Fold in the last dry bits with a rubber spatula and add 3/4 cup of the smashed Cadbury eggs.

Add the batter to your greased baking dish. Spread it evenly. Sprinkle the rest of the Cadbury eggs over the top (you may have a little bit left) I like to sprinkle the shattered shell pieces over the top as well.

Bake for 35 minutes or until the brownies are set and a toothpick comes out almost clean with maybe a few moist crumbs. Depending on your oven & baking pan, it can be anywhere from 35–50 minutes. Just go by the toothpick!