In a very large bowl, combine butter and cream cheese. Beat with an electric mixer on medium to high speed for 30 seconds. Add granulated sugar and salt. Beat until light and fluffy, scraping side of bowl occasionally. Beat in the 1 teaspoon lemon peel, the vanilla, and lemon extract until combined. Beat in cornstarch. Beat in as much of the flour as you can with the mixer. Using a wooden spoon, stir in any remaining flour. Divide dough in half. Cover and chill for 1 to 2 hours or until dough is easy to handle.

Preheat oven to 375 F. On a lightly floured surface, roll out one of the dough portions to an 1/8-inch thickness. Using a round 2-1/2-inch cookie cutter, cut out dough. Place dough rounds 1 inch apart on an ungreased cookie sheet.

Spoon 1/2 teaspoon of the jam onto the center of each round. To shape fans, bring opposite sides of each dough circle up over the jam and pinch them together where they meet, forming a point at one end.

Bake in the preheated oven for 8 to 10 minutes or until edges are lightly browned. Cool on cookie sheet for 1 minute. Transfer cookies to a wire rack; let cool. Repeat with the remaining dough portions. If desired, sprinkle cookies with additional lemon peel before serving. Makes about 54 cookies.

To Store: Layer cookies between waxed paper in an airtight container; cover. Store in the refrigerator for up to 3 days or freeze for up to 1 month.