Preheat the oven to 350 F.

Line two baking sheets with parchment paper or a silpat mat.

In the bowl of an electric mixer, cream together the butter and sugar until light and fluffy, 3-5 minutes.

Mix in the egg and mix until combined.

Add in the discard and vanilla extract and mix until combined.

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

Add the flour mixture to the butter mixture and mix until just combined. The dough should be slightly tacky but manageable.

Scoop out a scant 1 Tablespoon worth of dough and roll into a ball, and then roll in granulated sugar.

Place the balls of dough 2″ apart on the baking sheet.

Use your finger to gently depress a hold into the center of the cookie. You don’t want to go all the way through the cookie, but enough to make a nice sized well for the jam.

Spoon in about 1/2 teaspoon worth of jam into the hole. You don’t want to overfill, it won’t take much.

Bake the cookies for 12-14 minutes, until the edges are just starting to turn golden.

Allow to cool on the sheet for 10 minutes before transferring to a wire rack to cool completely.