Preheat the oven to 325F then grease a 10-inch cast iron skillet with nonstick spray and set aside.
In a medium saucepan, melt the butter over medium heat. Continue to cook, stirring and swirling the pan occasionally, until the butter turns golden brown and has a nutty aroma. Remove from heat and let cool to room temperature in a separate bowl.
2/3 cup butter
Add the granulated sugar, brown sugar, and brown butter to a large bowl and mix to combine.
1 cup brown sugar, 1/2 cup granulated sugar
Add in the eggs and vanilla extract and whisk to combine.
2 egg, 2 tsp vanilla extract
Mix in the flour, baking soda, and salt just until the flour mixture disappears then fold in the chocolate chips and the Cadbury eggs.
1 & 3/4 cup flour, 1/4 tsp baking soda, 1 cup Cadbury eggs, 1/2 cup Chocolate chips
Bake in the preheated oven for 27-30 minutes. The edges will be slightly brown and the center will look a little undercooked but will continue to cook as it cools down.
Allow the pizookie to set for 30 minutes before topping it with ice cream and enjoying!