1. Preheat oven to 375°F (190°C) and line a cookie sheet with parchment paper or a silicone baking mat.
2. Combine the flour, cornstarch and salt in a medium sized bowl. Set aside.
3. In a large mixer bowl, beat the butter until smooth.
4. Add 3/4 cup of the powdered sugar and mix until well combined and smooth.
5. Add the vanilla and coconut extracts and mix until well combined.
6. Add the dry ingredients and mix until the dough comes together.
7. Stir in the toasted coconut.
8. Scoop tablespoon sized balls of dough and shape into a ball. Place on the prepared cookie sheet 1-2 inches apart.
9. Bake for 7-10 minutes, or until the bottoms are just lightly brown.
10. Remove from the oven and allow to cool until you can handle them.
11. Add the remaining 1 1/4 cups (144g) powdered sugar and sprinkles to a small bowl and roll each cookie in it until well coated.
12. Allow the cookies to cool completely before serving. The powdered sugar melts onto the cookies a bit when they’re still warm. You might want to re-roll the balls again after they cool and the powdered sugar is done melting. Store in an airtight container.