Preheat the oven to 375 °F. Lightly coat a 12-cup muffin tin with cooking spray.
In a small bowl make the topping by combining flour, sugar substitute, coconut and butter with a fork. Set aside.2. In a small bowl make the topping by combining flour, sugar substitute, coconut and butter with a fork. Set aside.
In a medium bowl make the batter by whisking together flour, sugar substitute, baking powder, and salt. Stir in coconut. Add eggs and vegetable oil and beat by hand until just combined. Stir in pineapple.
Pour batter into prepared muffin tin. Top each muffin with a little of the crumb mixture. Bake for 20 to 25 minutes or until lightly browned and a toothpick inserted in the center of a muffin comes out clean.
*Gluten-Free Flour Blend: Combine 2 cups rice flour, 2/3 cup potato starch, 1/3 cup tapioca flour and 1 teaspoon xanthan gum.
Store in container with tight-fitting lid; stir before using.
Makes 3 cups.