1. Make the Dough

• In a large bowl, cream together the softened butter and cream cheese until smooth and fluffy (2–3 minutes).
• Add sugar and continue beating until light and creamy.
• Mix in the egg yolk and vanilla extract until fully combined.
• In a separate bowl, whisk together flour, baking powder, and salt.
• Gradually add dry ingredients to the wet mixture, mixing until a soft dough forms.
• Divide dough into two equal portions, flatten each into a rectangle, wrap in plastic, and chill for at least 2 hours or overnight.

2. Prepare the Jam Filling

• If your jam is runny, stir in a little cornstarch and heat briefly in a saucepan until thickened.
• Let jam cool completely before using to prevent dough from becoming soggy.
• Stir in lemon zest if desired for added brightness.

3. Roll and Fill the Dough

• On a lightly floured surface, roll one portion of dough into a rectangle approximately 1/8-inch thick (about 10×8 inches).
• Spread a thin, even layer of jam over the surface, leaving a 1/2-inch border on all sides.
• Starting from the long edge, gently roll the dough into a tight log.
• Wrap the log in plastic wrap and chill for another 30–60 minutes to firm up for cleaner slicing.
• Repeat with the second portion of dough.

4. Slice and Bake

• Preheat oven to 350°F (175°C) and line baking sheets with parchment paper.
• Slice chilled dough logs into 1/4-inch thick rounds and place cookies 2 inches apart on baking sheets.
• Optional: Brush edges lightly with egg wash or sprinkle with chopped nuts or sparkling sugar.
• Bake for 10–12 minutes or until edges are lightly golden.
• Cool on baking sheet for 5 minutes, then transfer to a wire rack to cool completely.

5. Decorate and Serve

• Once cooled, dust cookies lightly with powdered sugar if desired.
• Arrange on a platter or package in gift boxes for sharing.