Preheat the oven to 400°F. Line the bottom of a loaf pan with parchment paper and lightly grease the sides with a thin film of the melted coconut oil (use a small amount from the 1/4 cup measured for the batter). Set the pan aside.
Spread the 1/4 cup unsweetened coconut flakes in a single layer on a small, parchment-lined baking sheet. Toast in the 400°F oven until lightly browned, about 3–4 minutes, watching closely so they do not burn. Remove and let cool.
In a small bowl, combine the toasted coconut flakes with 1 tablespoon coconut sugar. Set this toasted coconut mixture aside. Reduce oven temperature to 350°F.
In a large bowl, whisk together the sifted coconut flour (1/2 cup + 2 tablespoons, 63 g), 1/4 teaspoon baking soda, 3/4 teaspoon baking powder, and 1/2 teaspoon salt. Stir in the toasted coconut/coconut sugar mixture until evenly distributed.
Measure and set aside 1 tablespoon of the dry flour/coconut mixture (from step 4) in a small bowl for the pineapple.
In a separate large bowl, use an electric hand mixer to beat together 1/4 cup honey, the 1/4 cup melted coconut oil, the 6 eggs, the zest and juice of 1/2 lime, and 1 teaspoon pure vanilla extract until smooth and combined.
Prepare the pineapple: place the drained crushed pineapple (1 can, 20 ounces) in a clean kitchen towel or several layers of paper towel and squeeze out as much liquid as possible so the pineapple is fairly dry.
Put the squeezed pineapple in a medium bowl and stir in the reserved 1 tablespoon of the dry flour/coconut mixture and the remaining 1 tablespoon honey. Break up any large clumps so the pineapple pieces are separated.
Slowly add the dry ingredients (from step 4) to the wet ingredients (from step 6), mixing with the electric mixer on low speed or folding with a spatula until well combined and no dry streaks remain.
Fold the pineapple mixture (from step 8) into the batter until evenly distributed. Let the batter rest for 10 minutes to allow the coconut flour to absorb moisture and thicken.
While the batter rests, make the macadamia streusel: in a small bowl combine 1/3 cup finely chopped macadamia nuts, 2 tablespoons coconut flour, 2 tablespoons coconut sugar, and 1 tablespoon melted coconut oil. Stir until the oil coats the mixture and it holds together loosely.
After the batter has rested, pour it into the prepared loaf pan and spread evenly. Sprinkle the macadamia streusel evenly over the top and gently press it into the batter so it adheres.
Bake at 350°F for 30 minutes. Tent the loaf loosely with foil and bake an additional 10–15 minutes, or until a toothpick inserted in the center comes out clean.
Remove the loaf from the oven and let it cool completely in the pan before lifting out, removing parchment, and slicing.