PREP: Preheat oven to 350 degrees F. Line two large trays with parchment paper or a Silpat liner and set aside.
COCONUT MACAROONS: In a very large bowl, add in the sweetened coconut flakes, flour, vanilla, and salt. Scoop out every bit of the sweetened condensed milk into the bowl. Use hand mixers to beat ingredients until just combined; do not overmix. Use a large cookie scoop (1-1/2 tablespoons in size) to get about golf ball-sized compressed (press into the cookie scoop) cookies.
The cookie scoop will get sticky and need to be washed a few times in the process. I also like to spray it with nonstick spray or use another spoon to help coax it out of the cookie scoop. You can leave the cookies as is right out of the scoop (for a more rustic appearance) or quickly roll them with your hands for a nicer appearance.
BAKE: Place cookies on the prepared sheet pans, 1 inch apart. Bake for 11 to 14 minutes or until coconut is lightly toasted on top and bottoms are a very light brown. Don't overbake! Remove and allow to cool on the pan for 5 minutes before gently moving them with a metal spatula to a cooling rack.
OPTIONAL CHOCOLATE: If you want to dip these in chocolate, wait for the cookies to fully cool. Then add the chocolate chips and coconut oil to a microwave-safe bowl and microwave in bursts of 20 seconds, stirring in between burst for 20-25 seconds until the chocolate is melted and smooth. Remember, chocolate is melting even outside of the microwave, so stir for a while to ensure it doesn't get burned. Transfer about 1/4 cup (just eyeball it) of melted chocolate to a plastic bag. Seal the bag without air in it and set aside.
DIP: Generously dip the bases of the cooled cookies in the remaining melted chocolate; then transfer dipped cookies back to your parchment paper-lined trays. Use scissors to cut a tiny tip off the bag with the remaining melted chocolate; drizzle that chocolate over the cookies. Allow to set up at room temperature.
STORAGE: These cookies will stay fresh, tightly covered, at room temperature for up to 3 days, or in an air-tight container in the fridge for 5-7 days. We like these cookies best within 1-2 days of being made. These cookies freeze and defrost really well without the chocolate!