Preheat oven to 350° F. Line a baking sheet with oven-safe parchment paper to prevent sticking Roll each piece of dough between your hands to shape into a smooth ball. Lay out on baking sheet 2-3 inches apart.
Bake for 10 minutes. Cookies should be almost cooked, but still doughy in the middle.
CAREFULLY use your thumbs to make a heart shaped indent in the dough. The pan and dough will be very hot, so take extra caution. You can also use a spoon to do this, but I've found thumbs really do work best.
Add a small bit of jam to each indent. Just enough to fill it in, but try not to overfill.
Return to oven and bake for 2-4 more minutes, or until the edges are slightly crispy and the middles are set. Let cool fully before serving.
