How To make Marshmallow Roses and Leaves

10 ounces package large plain marshmallows

(about 40)
3 cups confectioner's sugar :

plus more if needed
green and pink paste or liquid food color cornstarch granulated sugar
1. Process marshmallows and 2 cups of the confectioners' sugar in a food processor until large crumbs form. Tip crumbs into a microwave-safe bowl and microwave on high 10 seconds. Carefully (mixture may be hot) start working the sugar and marshmallows with your hands, kneading, squeezing and pulling, until a slightly sticky paste forms. (This will take about 10 minutes.)
2. Knead in remaining 1 cup confectioners' sugar, microwaving mixture 2 to 3 times in 5 to 10 second increments to soften. When done, you should have a smooth elastic dough.
3. Form dough into a disk and cut 1/4 off. Knead green color into small portion, pink into the rest (colors dry slightly darker). If using liquid food color, you may need to work in some more confectioners' sugar. Wrap pink dough in plastic wrap.
4. Fill a pie plate or other shallow container with about 1/2 inch granulated sugar (this will safely support and hold leaves and roses while drying).
5. LEAVES: Lightly dust work surface and a rolling pin with cornstarch. Roll out green dough to 18x4 inches. Trim edges. Cut lengthwise into 3/4-inch-wide strips. Cut each strip diagonally into diamonds.
With sharp side of a small knife, mark veins on each leaf. Twist leaves gently, then set in sugar in pie plate.
ROSES: Roll out 1/3 the pink dough as thinly as possible (keep rest wrapped). Cut out several 3/4 inch circles, using a piping tube, bottle cap or other round cutter. Press a small amount (about 1/4 teaspoon) of the scraps into a thick "stem," about 1/2 inch high. Dust fingers with cornstarch. Press 1 circle of dough between fingers until thin, wavy- edged and about half again as wide. Wrap around stem. Continue adding petals (10 to 12), pressing them firmly against the stem. Break off stem. Set rose in sugar. Repeat with remaining dough.