Preheat the oven to 325°F. Beat the eggs and sugar until frothy. Then add the flour, vegetable oil, cocoa powder, baking powder, vanilla extract, and salt and stir until creamy. Pour the batter into a greased 9-inch springform pan.
Wrap the playing cards in aluminum foil.
Divide the cake into 6 even sections by sliding the cards into the batter.
Unwrap the chocolate eggs, crumble them up, and divide the pieces between 2 opposite chambers. Do the same with the Oreos and M&M's and bake the cake for 35 minutes.
Prepare the chocolate frosting by mixing the hot cream and chocolate chips together. Let the frosting cool down a bit before moving on to the next step.
Remove the foil-wrapped playing cards from the cake and spread about a tablespoon of frosting on each cake slice. Put the rest of the frosting in a piping bag and use it to decorate the cake. Feel free to top off the cake with more Oreos, M&M's, and Kinder Surprise Eggs.