Phineas and Ferb Birthday Cake

My kids love Phineas and Ferb, so I had a long line of expert advisers ready to help me correct a smile or a frown on the figurines I made for this cake: including Perry the Platypus, Isabella, Candace, Jeremy, Baljeet, Major Monogram and Dr. Doofenshmirtz. We built a roller coaster too! Oh and the important bit! Inside are vanilla and chocolate cake tiers both have Oreo Cream filling.