Judging by Applejack's expression, she did not seem to know what exactly it was they were doing. Which does beg the question - what exactly where they planning to do by turning into a giant apple-pie anyway?
"Step 1 - We do the fusion-dance!" "The what-now dance?" "Step 2 - We turn into a giant apple-pie! Then, step 3 will be to-" "Wait, what?" "...And that'll be Soarin's best birthday ever!" ". . ."