When we first found these, we though them to be vintage stickers. We've since discovered that they were single die cuts made to top special Christmas cookies, be they stollen or gingerbread! These would normally be attached with icing (used like glue).
Because these are vintage and we're not sure of their complete provenance, we would suggest that you not use them on food directly.
Each little die cut measures 2-5/8 inches high by about 1 inch wide. It is very lightly embossed and at Santa's foot, the style number reads 38681.
They are nicely cut and in great shape for their age. we expect that they are from the 1940s or earlier.