In a medium bowl, whisk together the flour, chamomile tea and salt. In a small bowl, whisk together the heavy cream, egg yolks and vanilla.
In a stand mixer fitted with the paddle attachment, cream the butter and granulated sugar together on medium speed until light and airy, about 2 minutes. Alternate adding the flour mixture with the cream mixture in 3 additions, starting and ending with the flour mixture until the cookie dough just comes together with no dry patches.
Turn half of the dough out onto a large sheet of plastic wrap. Shape it into a 3-by-6-inch log. Wrap tightly and repeat with the remaining dough. Refrigerate until the dough is firm, at least 2 hours or up to 3 days (the cookie log can also be frozen for up to 3 months; defrost overnight before slicing).
Adjust one oven rack to the upper-middle position and another oven rack to the lower-middle position. Preheat the oven to 375°. Remove the dough logs from the refrigerator and set aside at room temperature for 5 to 10 minutes. Sprinkle the turbinado sugar on a work surface, unwrap the dough logs, and roll them through the sugar until they are lightly coated with sugar on all sides. Slice the log crosswise into ¼-inch-thick rounds.
Line 2 baking sheets with parchment paper and place the cookies 1 inch apart on the prepared baking sheets. Set one baking sheet on the upper oven rack and the other on the lower rack. Bake for 7 minutes, then rotate the pans, moving the pan from the lower rack to the upper one, and the one from the upper rack to the lower one. Bake until golden-brown around the edges, 6 to 7 minutes longer. Remove the baking sheets from the oven and cool the cookies for 5 minutes before using a metal spatula to transfer them to a wire rack to cool completely.
Turn half of the cookies bottom side up. Spread ½ teaspoon of the Bonne Maman Golden Plum Mirabelle Preserves across the cookies. Top each with another cookie, lightly press together and serve.
Yield: 2 dozen cookie sandwiches
Cook Time: 14 minutes, plus 2 hours refrigeration time