This is not my original design! Client sent me the pic. & she wants exactly the same for her wedding anniversary.
I google & find out, the designer of the cake is from Amber Mckenney.

This is a small cake, bottom tier is 4" square cake, middle is 3" square, tennis ball is from rice krispies covered in fondant.

Figurines & tennis rackets made from fondant, inside is tiramisu cake.