Prepare and bake the chocolate cake in a 9×13 baking dish according to the package instructions. Allow the cake to cool completely, then use the handle of a wooden spoon to poke holes in the cake.

Make the cream filling by pouring the corn syrup, butter, vanilla, and salt in a medium saucepan. Cook over medium low heat until the butter is melted and the ingredients are just beginning to simmer.

Reduce the heat to low and slowly add the powdered sugar. Whisk the mixture until the sugar is fully incorporated, then remove from heat.

Spoon about half of the creme mixture into the holes on the cake filling about halfway. Do not completely fill each hole, we will be adding more later.

Add the yellow food coloring to the remaining creme filling and stir to combine. If the filling begins to harden, reheat it over low heat until it melts again

Spoon the remaining yellow filling over the top of the holes in the cake. Let the cake rest at room temperature for at least one hour, until the filling is set.

Spread the chocolate frosting over the top of the cake.

Cut six of the Cadbury eggs in half and decorate the top of the your Cadbury chocolate cake with the twelve egg halves. Finely chop the remaining eggs and sprinkle the pieces over the top of the cake. Serve