Whisk together the flour, baking powder, and salt. Set aside.
Using an electric mixer on medium speed, beat the butter, cream cheese, and sugar until light and fluffy. Add the eggs, one at a time, mixing well after each addition. Mix in the vanilla.
Reduce mixer speed to low. Gradually add the flour mixture, mixing just until combined.
Chill the dough for an hour (or up to overnight).
Preheat the oven to 350°F (175°C). Line baking sheets with parchment paper or silicone liners.
Using about 1 & 1/2 tablespoons of dough at a time (I use a #40 scoop.), roll the dough into balls and place 2 inches apart on the prepared pans.
Make an indentation in the middle of each cookie, using your thumb or a small measuring spoon.
Fill each indentation with about 1/2 teaspoon of jam. If your kitchen is warm, place the pans in the refrigerator for about 15 minutes.
Bake one pan at a time for 12 to 15 minutes, or until the edges are lightly browned.
Place the pans on wire racks and let the cookies cool for 5 minutes. Then transfer the cookies from the pans to a wire rack to cool completely.
If desired, sprinkle the cookies with confectioners' sugar before serving.
Notes
Measuring flour: For the best consistency, measure by weight or use the spoon-and-sweep method. Too little flour can make the dough overly soft.
Chilling time: If your dough feels too sticky to handle after the first chill, give it extra time in the refrigerator. It should feel cool and slightly firm to the touch before shaping.
Cream cheese temperature: Let the cream cheese soften just enough to blend smoothly with the butter. It should be pliable but not warm or glossy. Overly soft cream cheese can make the dough sticky.
Rolling tips: Roll dough with cool, dry hands. If it still sticks, dust your palms lightly with flour or confectioners’ sugar, or chill the scooped dough briefly before shaping.
Jam options: Thicker jams and preserves hold their shape better during baking. If your jam is runny, stir in a small pinch of cornstarch or briefly simmer to thicken.
Storage: Keep cookies in an airtight container at room temperature for up to a week. They can also be frozen (filled or unfilled) for up to 2 months. Thaw at room temperature before serving.
Make ahead: You can refrigerate the dough up to 24 hours in advance. Let it soften slightly before scooping and shaping.