To make the modeling chocolate: Professionals call modeling chocolate by the name chocolate plastic. Melt the chocolate and cocoa butter over a double boil. Bring the ingredients for the simple syrup to a boil. Place the corn syrup in a bowl and stir in the hot simple syrup. Pour this over the melted chocolate. Stir until it thickens. Place it in the refrigerator for at least one hour. The modeling chocolate will have the consistency of play dough when you work it with your hands. Divide it into three pieces. Use the food color paste to color one piece pink and one piece green. Work the food color paste into the modeling clay to distribute the color until it is the desired color.
To make the ribbon: Take a ball of each color. Use the palms of your hands to roll each ball into a rope about 1/2-inch thick. Place the ropes side by side and gently press together. Use a rolling pin to roll out the ropes to create a tri-colored ribbon. Use cornstarch to "flour" the work surface. The rolled chocolate should be about 1/8-inch thick. Cut a strip about 30 inches long and about 11/2-inches wide and wrap it around the brim of the hat. You may need to trim the ends.
To make the leaves and rose petals: Roll out each colored chocolate plastic using cornstarch to "flour" the work surface. The rolled chocolate should be about 1/8-inch thick. To make the flowers, use 2-inch diameter cutter to cut circles from the rolled chocolate. You need to gently thin the top edge of each circle and you can do that with the end of an offset spatula or a hard-boiled egg. Gently press the spatula or egg against the top of the flower to thin the edge (like a real flower petal). Use 11/2 and 2-inch oval cutters to cut out the leaves. You can also do this with a paring knife. Use the back of a paring knife dipped in cornstarch to make the veins of the leaves.
To make the center: All flowers have some kind of center. Use your fingers to shape a cone-shaped bud for the center of your rose. (Recipe continues on to Part Two)