Marshmallow Fondant

Step 1
Place butter in a shallow bowl and set aside.

Step 2
Place marshmallows in a large microwave-safe bowl and microwave on high to start melting the marshmallows, 30 seconds to 1 minute.

Step 3
Carefully stir water and vanilla into hot marshmallows; stir until the mixture is smooth. Slowly beat in confectioners' sugar, 1 cup at a time, until you have a sticky dough. Reserve 1 cup confectioners' sugar for kneading. The dough will be very stiff.

Step 4
Rub your hands thoroughly with butter and begin kneading the sticky dough. As you knead, the dough will become workable and pliable. Turn the dough out onto a working surface dusted with confectioners' sugar and continue kneading until the fondant is smooth and no longer sticky to the touch, 5 to 10 minutes.

Step 5
Form the fondant into a ball, wrap it tightly in plastic wrap, and refrigerate, 8 hours to overnight.

Step 6
To use, allow the fondant to come to room temperature and roll it out onto a flat surface dusted with confectioners' sugar.