Preheat oven to 350 degrees. Line a standard muffin tin with paper cupcake liners.
Combine the chopped apple, 2 tablespoons melted coconut oil, coconut palm sugar, and 1 tablespoon cinnamon flavored agave in a medium saucepan and bring to a boil. Let simmer for 8 – 10 minutes or until the apples are softened but still retain their shape. Let cool.
Whisk together the coconut flour, salt, and baking soda. In a mixing bowl, whisk together the eggs, remaining ½ cup coconut oil, remaining ¼ cup cinnamon agave, and vanilla. Add the coconut flour mixture to the liquid ingredients and whisk well until smooth. Stir in the apple mixture. Divide the batter among the prepared muffin cups, filling almost full. Bake for 20 – 25 minutes or until the cupcakes feel firm to the touch and a toothpick inserted into the center comes out clean. Let cool in the pan. While cupcakes cool, prepare the frosting.
Frosting
Pour the cinnamon agave into a high-sided pan (use a pan a lot larger than you think you will need as the agave increases in size as it boils) and bring to a boil. Continue to boil for 3 minutes (it should have large bubbles or reach 225 degrees on a candy thermometer).
Combine the egg whites and salt, beat in a mixer on low until foamy then increase the speed to high and beat until stiff peaks form. Turn the mixer to low, carefully pour in the agave then turn the mixer back to high and beat until cool, about 7 minutes. Beat in the vanilla.
To assemble, generously frost the cooled cupcakes with the frosting.