1. 1. Preheat the oven to 375°F (190°C). Line a baking sheet with parchment paper.

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

3. 3. In a large bowl, beat the butter and granulated sugar until light and fluffy, about 2-3 minutes.

4. 4. Beat in the egg and vanilla extract until well combined.

5. 5. Gradually add the dry ingredients to the wet ingredients and mix until a dough forms.

6. 6. Roll the dough out on a lightly floured surface to about 1/4 inch thickness.

7. 7. Use a round cookie cutter or biscuit cutter to cut out circles from the dough.

8. 8. Place half of the circles on the prepared baking sheet. Spoon about 1 teaspoon of strawberry jam into the center of each circle.

9. 9. Top each filled circle with another dough circle, pressing the edges to seal.

10. 10. Bake for 12-15 minutes, or until the cookies are lightly golden.

11. 11. Let the cookies cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.

12. 12. Dust the cooled cookies with powdered sugar before serving.