Use a circle cutter (that's the same size as your Oreos) to cut out round shapes.
Use a spatula to spread buttercream icing on top of each Oreo cookie.
Place the circular fondant pieces on top of each frosted cookie and press gently to secure properly.
Use edible markers to draw details.
Use different colors of fondant for different types of sports balls. For basketball cookies, use orange colored fondant.To baseball cookies, use white fondant and red edible marker to draw details.For volleyballs, use light blue fondant and black edible marker to draw details.For soccer balls, use white fondant and black edible marker to draw details.For a tennis balls, use green fondant and and rolled yellow fondant for the details.
Read all my tips above.
Leftovers can be stored in a cardboard box at room temperature for up to 3 days.