I love your cake!! I want to make it for my sons first birthday that's coming up. I wanted to know what pan size did you use for this cake. Thank you!

Thank you Stephanie! I believe I used a 4" buttercream for the top that doubled as the smash (that's why it was in buttercream) a 8" & 12". They are off set to make room for construction theme. Kind of like stairs . hope that helps :-) The truck scooper/claw was actually digging into the cake. I made a hole and then used chocolate icing and oreos for dirt inside of hole (and sticking to dump truck).  

I also made a fondant covered cake board to put the topper on when it was time for the smash cake. Just attached It with some buttercream :) leat sit 5 mins in fridge and was good to go!