Preheat oven to 325℉. Sprinkle coconut in a single layer onto a large baking sheet. Toast in oven for 8-10 minutes, stirring every 3-4 minutes until golden brown. Pour toasted coconut into a shallow bowl and set aside to cool.

In a large mixing bowl, use a handheld mixer on medium-high speed to cream together butter, granulated sugar, and brown sugar until light and fluffy. Add applesauce, vanilla, cream of tartar, baking soda, and salt.  Beat on medium until creamy and combined.

Add flour and combine on low until a soft dough forms. Fold in half of toasted coconut. Cover and refrigerate for 30 minutes.

Preheat oven to 350℉. Line a large baking sheet with parchment paper. Use a cookie scoop to portion dough onto baking sheet. Bake cookies for 11 minutes. Cool for 10 minutes on baking sheet before transferring to a wire cooling rack.

While cookies are cooling, prepare the frosting. In a medium mixing bowl, use a handheld mixer on medium-high speed to cream together cream cheese, butter, and vanilla until creamy. Mix in 1 cup of powdered sugar at a time until fully combined. Top each cookie with cream cheese frosting and top generously with remaining toasted coconut. Enjoy!