Preheat the oven to 325°F and melt 48 Kinder chocolate bars in a water bath or microwave.
Mix the eggs, sugar, baking powder, flour, vegetable oil, and milk together with a hand mixer.
Pour half of the cake batter into a second bowl.
Add the cocoa powder and ⅓ of the melted Kinder bars to one of the bowls and mix well.
Grease a 9-inch springform cake pan and alternate between pouring in the light cake batter and the chocolate cake batter. Bake for 60 minutes.
Once the cake has cooled, pour the rest of the melted Kinder bars over the entire cake.
Cut 20-30 Kinder chocolate bars into thirds vertically and press the pieces into the glaze to decorate the cake.