Preheat your oven to 350°F (180°C). Line two large baking sheets with parchment paper or silicone baking mats.

In a large bowl or a stand mixer fitted with the paddle attachment, cream the softened butter and granulated sugar together until light and fluffy, about 2-3 minutes.

Beat in the egg and vanilla extract until well combined.

In a separate bowl, whisk together the all-purpose flour, baking powder, and salt.

Gradually add the dry ingredients to the wet ingredients, mixing until just combined. The dough should be soft and slightly sticky.

Cover the dough and refrigerate for at least 30 minutes (or up to 3 days) to firm up.

Using a small cookie scoop or spoon, scoop out about 1 tablespoon of dough and roll it into a smooth ball. Place the ball on the prepared baking sheet, spacing them about 2 inches apart.

Using your thumb or the back of a teaspoon, gently press an indent into the center of each dough ball, being careful not to press all the way through.

Spoon about 1 teaspoon of your favorite jam into the center of each indentation.

Bake the jam drops for 12-15 minutes, or until the edges are lightly golden. Allow the cookies to cool on the baking sheets for 5 minutes before transferring them to a wire rack to cool completely.