In a large bowl, beat butter, sugar, vanilla, gelatin, and egg with mixer on medium speed. Once mixed, on low speed add in flour.
Shape dough into 1 1/4 inch balls and cover and refrigerate for one hour.
Dip top of the dough ball into multi colored sprinkles, then gently press down in the center of the "flower".
Heat oven to 375 degrees and on an ungreased cookie sheet, place balls about 2 inches apart. With a sharp knife, make six cuts on top of each ball about 3/4 of the way through to make six wedges. Spread wedges apart slightly to form flower petals (cookies with separate and flatten as they bake).