Make the Dough:

1. In a medium bowl, whisk together flour, baking powder, and salt. Set aside.
2. In a large bowl, beat butter and sugar until light and fluffy (2 minutes).
3. Mix in egg and vanilla extract, then gradually add the dry ingredients until a smooth dough forms.

Prepare the Raspberry Filling:

4. In a small saucepan over medium heat, stir together raspberry jam, lemon juice, and cornstarch until slightly thickened (2 minutes). Remove from heat and let cool.

Assemble the Cookies:

5. Roll out the dough into a 10×12-inch rectangle between two sheets of parchment paper.
6. Spread the raspberry filling evenly over the dough.
7. Roll the dough tightly into a log (starting from the long side). Wrap in plastic wrap and refrigerate for 1–2 hours, until firm.

Bake the Cookies:

8. Preheat oven to 350°F (175°C) and line a baking sheet with parchment paper.
9. Slice the chilled dough into ¼-inch thick rounds and place on the baking sheet.
10. Bake for 10–12 minutes, or until the edges are lightly golden.
11. Let cool completely before glazing.

Make the Glaze (Optional):

12. Whisk together powdered sugar, milk, and vanilla extract. Drizzle over cooled cookies.

Serve & Enjoy!

13. Let glaze set, then serve with coffee, tea, or milk!