Preheat your oven to 375°F (190°C). Prepare a 12-cup muffin tin by lining it with paper liners or greasing each cup.
In a large bowl, whisk together the whole wheat flour, rolled oats, shredded coconut, baking powder, baking soda, and salt until evenly distributed.
In a separate, medium-sized bowl, whisk together the egg, applesauce, cottage cheese, pineapple juice, honey or maple syrup, and vanilla extract until nicely combined and relatively smooth.
Pour the wet ingredients into the bowl with the dry ingredients. Using a spatula or wooden spoon, stir gently just until the dry ingredients are moistened and everything is combined. A few lumps are okay; do not overmix.
Gently fold in the finely diced pineapple until distributed throughout the batter.
Spoon the batter evenly into the prepared muffin cups, filling each cup about two-thirds full.
Bake for 18-22 minutes, or until a toothpick inserted into the center of a muffin comes out clean (a few moist crumbs are fine).
Take the tin out of the oven and let the muffins sit in the tin for a few minutes before carefully transferring them to a wire rack to cool completely.