Preheat oven to 350°F/180°C and line two baking trays with parchment paper. Set aside.
Brown the butter: Melt the butter in a medium sized pan over medium heat. Once it melts, it will crackle, then become foamy – continue mixing the butter while this happens to prevent burning. The butter will go from melted to golden brown quickly, and you'll know it's almost done when the aroma of browned butter arrives. The whole process should take about 5 minutes! Once golden, remove from heat and transfer to a glass bowl.
1/2 cup butter
In a large bowl, whisk in the melted and browned butter, brown sugar, and white sugar for one minute until combined.
1/2 cup dark brown sugar, 1/3 cup white sugar
Add in egg and vanilla and continue whisking.
1 egg, 1 tbsp vanilla
Fold in the flour, baking soda, baking powder, and salt using a spatula until just combined.
1 1/2 cups all-purpose flour, 1/2 tsp baking soda, 1/2 tsp baking powder, 1/4 tsp salt
Mix in the Kinder chocolates and chocolate chips.
1/2 cup Kinder chocolate, 1/2 cup semi-sweet chocolate chips
Scoop 6 cookie dough balls on each tray at a time. Bake for 12-15 minutes or until the edges are a light golden brown.
Top off with additional chocolates if desired. Cool the cookies on a cooling rack and enjoy!