Make the Dough:

1. Using a hand mixer, or a stand mixer fitted with a paddle attachment, at Medium speed, combine the butter and sugar. You don’t want to whip it until it’s fluffy, but just get it well-combined, about 2-3 minutes. Add the vanilla and combine until incorporated, abut 30 seconds. Sift the flour and salt over the butter mixture and beat at medium low until it begins to form a dough, a minute or 2.
2. Tear a sheet of plastic wrap about 20 inches long. Dump the dough out onto the sheet, and using the sheet, form the dough into a disk about 1-1.5″ thick. It will be 9-10 inches wide. Refrigerate the disk 30 minutes. 
3. Prepare the egg wash in a small bowl. Pour the coconut into a medium-sized shallow bowl or pie plate. Preheat oven to 350F (Conventional Oven) or 335F (Convection/fan).

Form the Cookies:

1. Line 2 cookie sheets with parchment or butter. After 30 minutes of chilling, remove the dough from the refrigerator and unwrap. Cut sections of dough that are 1-oz, 28.3g. (I used a kitchen scale and mine weighed 28 or 29g apiece.) Form the sections into a ball. Dip each ball into the egg wash. Then roll the egg-washed ball into the coconut, getting it nicely coated. Place the balls onto the lined cookie sheets, 12 per sheet.
2. Using your thumb, make an impression, or an indentation (maybe 1/2″ deep) into each ball. It will form into something like the shape of a volcano that has erupted. Place 1/4 teaspoon (1.5ml) preserves into each well. Once the pans are filled, bake in preheated oven until the cookies are just set, starting to color, and the coconut is nicely golden. If the coconut gets too dark, you will want to lower one temperature a bit. Bake 16-22 minutes. Mine were done at 18 minutes. If you bake 1 pan at a time, they will likely be done on the quicker side (16 minutes). Remove from oven. Let cool slightly on the pans for a few minutes, then remove to a cooling rack to cool completely.
3. Store cooled cookies in an airtight container, either at room temperate for 3-5 days, or in the freezer for up to 2 months.