In a large bowl, cream butter and sugar. Beat in the egg, sour cream and extracts. Combine the flour, baking soda and salt; gradually add to creamed mixture. Cover and refrigerate for 3 hours or until easy to handle.
On a lightly floured surface, roll out dough to 1/4-in. thickness. Cut with a floured 2-1/2-in. heart-shaped cookie cutter. Place 1 in. apart on ungreased baking sheets. Sprinkle with colored sugar. Bake at 375° for 8-10 minutes or until lightly browned. Remove to wire racks.