Preheat oven to 350 degrees with rack in the middle. Butter an 8x11 tart pan or spring form pan and line with parchment paper.
In a large bowl combine the flour, 3/4 cup of the coconut, 3/4 cup of the sugar, and salt. Stir in the melted butter and mix until dough is crumbly. Press the mixture into the pan, and bake for 15 minutes. Remove and set aside.
Combine the remaining 2 cups coconut, the remaining 1/2 cup sugar, and egg whites. Mix until well combined.
Evenly distribute most of the cherries across the the crust of the tart. Now drop little spoonfuls of the macaroon topping over the cherries (I dirty up my hands for this part), and mush/press the coconut topping around a bit into the spaces behind the cherries. You can let at least some of the colorful cherries pop through the topping for effect. Bake for about 20 minutes or until the peaks of the macaroon topping are deeply golden. Let tart cool and serve.