Preheat oven to 350 degrees F (175 degrees C). Grease and flour two 9 inch round cake pans.
Ignore instructions on cake box. In a large bowl, beat eggs, add 1 can pie filling and combine. Add cake mix and beat until well mixed. The batter will be stiff.
Pour half of the batter into each pan and spread evenly. Bake at 350 degrees F (175 degrees C) for about 25 minutes, or until a toothpick inserted into the center of cake comes out clean. Cool a couple of minutes, then turn layers out onto cooling rack. Cool completely before icing.
For the icing: Beat butter, cream cheese, and vanilla until smooth. Add confectioners sugar and continue beating until smooth.
Ice a layer, add the second layer, and finish icing the cake. Refrigerate until time to serve. Just before serving, pour the cherry pie filling on top and spread it gently to the edges. A few of the cherries will roll down the sides. That's what you want.