Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.
In a large mixing bowl, combine the peanut butter and sugar, mixing until smooth.
Add the egg, vanilla extract, baking soda, and salt, and stir until well combined.
Using a tablespoon, scoop out the dough and roll it into balls.
Place the balls on the prepared baking sheet, spacing them about 2 inches apart.
Use your thumb to create a small indentation in the center of each cookie.
Fill each indentation with about 1/2 teaspoon of fruit preserves.
Bake in the preheated oven for 10-12 minutes, or until the edges are lightly golden.
Allow the cookies to cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely.