Those are stickies. My grandmother taught my mom to make them, and my mom taught me and my sister when we were little, and now my mom is teaching Sally. There isn't much to making stickies—they're just leftover pie crust rolled out into tiny circles and filled with homemade jam. Usually we use strawberry jam, because we make so much of it every June, but I've made stickies with blueberry, rhubarb, and even lemon curd. The little pastries are homey and old-fashioned, and they're delicious.
You can see the process here pretty clearly: you take a little piece of leftover pie crust dough—it doesn't have to be more than a scrap, really—and roll it out. Then you grab a glass and cut the dough into circles. You spoon a little bit of jam onto one half of each little circle, leaving some space around the sides, then fold the other half over the jam and use a fork to press the edges. You use a knife to cut a few little steam slots on top, just like you would for pie, bake them for maybe 10 or 15 minutes, and you're finished.
When we made these, I was photographing while my mom and Sally were working, and Sally told us several things she wanted to make sure were in the story. First of all, she recommends licking the jam off the spoon. Also, a little jam might squeeze out of your sticky, and she wants you to know that's ok. And my mom wants to add that if you're after something a little less sweet, you can also fill the stickies with grated cheese, although she didn't think of that until she was a grown-up.