Cream together butter and sugars on medium-high speed. Beat in the egg and vanilla. Add the flour and salt on low speed. Beat in the lemon juice, lemon zest, and cranberries. The dough will be fairly sticky.
Divide the dough in half. Turn out one half of the dough on a lightly floured surface. Roll and shape the dough into a log roughly 2-inches in diameter. Repeat with the second half of the dough. Tightly wrap both dough rolls in plastic wrap and chill in the refrigerator for a minimum of 3 hours or up to 24 hours (we prefer to chill ours overnight to let the lemon flavor really shine!). Do not skip this step!
Once you are ready to bake the cookies, preheat the oven to 350℉. Line two baking sheets with parchment paper or silicone baking mats.
Use a sharp knife to slice each roll into 12 roughly equal pieces about ½ inch thick. The dough may flatten slightly when cut, so you may need to reshape the slices back into disks. Place 12 cookies on each baking sheet.
Bake cookies for 13-15 minutes, or until lightly brown. For the best results, bake one sheet at a time. Cool the cookies on the baking sheet for 5 minutes before transferring to a cooling rack to finish cooling.
Place the white chocolate in a microwave safe bowl. Warm the chocolate for 30 seconds at a time in the microwave, stirring between each 30 second burst, until melted or melt in a double boiler. Drizzle or dunk the cookies in the chocolate. Return the cookies to the cooling rack until the chocolate sets, about 30-60 minutes.