Makes 1 box.
In advance, prepare truffles following recipe directions. Set aside.
Preheat oven to 350°F. Prepare gingerbread dough; roll out 1/4 in. thick. Using bottom of pan as a pattern, cut out one heart each for box bottom and lid. For box sides, cut a 1 3/4 x 20 in. long strip. Spray pan with vegetable pan spray. Position one heart cookie dough in bottom of pan; press to fit. Position strip upright along sides of pan. (If strip breaks, press together and blend seams with fingers.) Prick bottom and sides with fork. Bake 13-16 minutes or until lightly browned. Let cool in pan on cooling grid; unmold.
Position lid heart cookie on cookie sheet. Using second largest heart cookie cutter, imprint center of cookie, pressing firmly, but not through the cookie. Bake 9-12 minutes; let cool.
Outline imprint with cookie icing; let set. Warm icing to flowing consistency in warm water; fill in outline area. Position sprinkles on icing heart; let set. Fill box with truffles. Position cookie lid.