Make the Cookie Dough: In a large bowl, cream the softened butter with an electric mixer on high speed. Add the sugars to the butter mixture and mix until creamed together with the butter, about 1 minute. Add the vanilla and eggs and mix until just combined. Scrape the sides of the bowl with a rubber spatula to get everything mixed in. Add the lemon juice and zest, and mix until just incorporated. Add the dry ingredients last, and mix until a dough forms. Chill the Dough: The dough needs a bit of a longer chill time so that it can contain the blueberry preserves when it bakes. You must pre-scoop your dough balls – thoroughly chilled dough is hard to scoop, and you'll re-warm the dough in the process. (You can chill about 30 minutes first to make scooping a bit easier, though.)Scoop the dough into balls that are 60-65 grams with a medium cookie scoop (about 3 tbsp), then indent the centers with the back of a tablespoon measuring spoon. This will be hard to do when the dough is solid later on. Place in an airtight container to chill in the fridge for at least 4 hours, or up to 24 hours. You can also freeze the dough balls (rolled in sugar and indented) for 2 hours or up to 2 months. (Cookies can be filled & baked from frozen.) Assemble the Cookies: Preheat your oven to 365° F. Mix the sugar and lemon zest together in a small bowl, rubbing the zest into the sugar. Roll the dough balls generously in this mixture, then place on a parchment paper or silicone baking mat lined sheet pan. Fill each dough ball with 1-2 tsp of the Grandma Hoerner’s Organic Blueberry Preserves.. Bake: Bake the cookies for 11-13 minutes. The edges should appear just set, and the centers will appear a tad underdone. The cookies will set up as they cool. Let cookies cool on the baking sheet about 10-15 minutes, then transfer to a cooling rack to cool completely before decorating and serving. Serve + Store: Mix the lemon glaze ingredients and drizzle over the cooled cookies. Cookies can be stored in an airtight container at room temp for 1-2 days, and after that I recommend refrigerating. Let cookies come back to room temp a bit before serving.