1. Cut marshmallows with kitchen scissors into slices. Marshmallows will form a petal shape as they are being cut.
2. Dip into colored sugar and set aside.
3. Combine icing ingredients, mixing until smooth.
4. Adjust sugar and/or liquid to achieve spreadable consistency.
5. Working with one cupcake at a time, spread a layer of icing over the top.
6. Before the icing hardens, quickly press marshmallow slices onto each cupcake, overlapping slightly to form petal design.
7. Push half a toothpick into the center of each flower and place a mini marshmallow onto the toothpick tip.