Wizard of Oz Cupcake Toppers
How I made a couple of these Wizard of Oz cupcake toppers
Wizard of Oz Cupcakes

I would recommend that you use gumpaste to make the round yellow plaque (brick road) that forms the backdrop and then use fondant (or modelling chocolate) to make the actual faces and decorations.

Check out this video tutorial on how to make modeling chocolate or this live session recording that is all about modeling chocolate and making a rose, too.

Satin Ice Gumpaste
Satin Ice is a premium quality gum paste for creating incredible cakes for weddings, birthdays, novelty, and special-occasion cakes. It is used as a modeling paste to create decorative borders, flowers, figurines, drapes & bows.
CK Products Brick Impression Mat
These impression mats are great for rolled fondant, gumpaste, and buttercream. Design extends to the edge, making it easy to use on the sides of cakes (for buttercream) or to make a continuous design (with fondant or buttercream). Dimensions: 7⅝" x 5⅞" x ⅛"
Fondant Rolling Pin
Smooth, Non-Stick Rolling Pin with Thickness Bands is perfect for precisely rolling out fondant or covering cakes with rolled fondant.
Ateco 5357 Plain Edge Round Cutters
Ateco 5357 Plain Edge Round Cutters in Graduated Sizes, Stainless Steel, 11 Pc Set. Complete with a tin storage box to reduce clutter, this set of 11 round, stainless-steel cookie cutters comes in handy for all seasons. The cutters range in size from 3/4 inch high to 3-5/8 inches high, and they have rolled edges on top to protect fingers during the cutting process. They're constructed to be long-lasting and are dishwasher-safe.
CAI Tylose Powder
CAI Tylose Powder is an enhanced Tylose Powder that provides the paste with binding and structural properties that makes the paste last longer. Flowers and showpieces dry remarkably fast, excellent to use in pastillage.
Bakerpan Food Coloring Markers, Black
Bakerpan Food Coloring Markers can be used again and again just like regular markers! For best results, draw on foods which have a smooth dry surface.
Silicone Molds - Bows
JETEHO Set of 2 Mini Bows Silicone Mold for fondant, Sugar paste, chocolate etc.