Steps

1. 1

   In the large bowl of a stand mixer fitted with the paddle attachment, beat butter and confectioners’ sugar on medium-high speed, scraping bottom of bowl as needed, until pale and fluffy, about 2 minutes. Add egg yolks and beat just until combined. Add vanilla and salt and beat until no streaks of vanilla remain.With the mixer on low speed, add flour and beat on medium speed until airy and fluffy, about 3 to 5 minutes.

2. 2

   With the mixer on low speed, add flour and beat just until combined; do not overmix.

3. 3

   Transfer dough to piping bag fitted with star tip. Onto corners of 2 baking sheets, pipe 2 or 3 small dots of dough (to prevent parchment from moving), then place 2 sheets of parchment over dots. Pipe 1 3/4" rosettes, 3" lines, 1 1/2" stars, and 3" S-shaped cookies, as desired. Using a small spoon, make a slight indent in the center of star cookies.

4. 4

   Loosely cover with plastic wrap. Freeze until firm, about 20 minutes, or refrigerate at least 30 minutes and up to overnight.

5. 5

   Arrange racks in upper and lower thirds of oven; preheat to 350°. Bake cookies, rotating sheets top to bottom and front to back halfway through, until puffy and edges are lightly golden, 15 to 18 minutes. Transfer cookies to wire racks and let cool.

6. 6

   Meanwhile, in a small microwave-safe bowl, microwave chocolate in 20-second increments, stirring between each, until melted and smooth, about 1 minute total.

7. 7

   Dip half of line cookies into chocolate, then return to baking sheets. Top chocolate with sprinkles. Spread jam on flat sides of some line cookies and sandwich together, if desired. Dip half of some S-shaped cookies and rosettes into chocolate, then return to sheets. Top chocolate with sprinkles. Decorate remaining rosettes with sprinkles. Fill indent of stars with cherries or jam.