In a medium bowl, stir together the flour, baking powder, and salt.

In a large bowl, cream together the softened butter, 1/2 cup granulated sugar, and vanilla extract until light and fluffy.

Add the egg and beat well until fully incorporated.

Gradually beat in the flour mixture until just combined.

Chill the dough for one hour.

Preheat your oven to 350°F and line baking sheets with parchment paper or silicone baking mats.

Place the remaining 1/4 cup of granulated sugar in a small dish. Roll dough into 1-inch balls, then roll the balls in sugar before placing them 2 inches apart on the prepared baking sheets.

Make an indentation in the center of each ball using your thumb or the end of a wooden spoon handle.

Bake for 13-16 minutes until the edges are slightly browned.

Remove the cookies from the oven and allow them to cool on the baking sheets for a few minutes before transferring to wire racks.

Spoon jam into the center of each cookie.

To make the glaze, combine confectioners' sugar, vanilla extract, and enough water to reach a drizzle-able consistency.

Store the cookies in an airtight container in a cool place with parchment paper between layers.