Preheat the oven to 350° F
Prepare a 12-muffin tin with muffin cups or a thin layer of coconut oil (or butter)
In a small saucepan, over medium heat, melt the butter. Remove the pan from the heat and whisk in the liquid sweetener, ground cardamom, cinnamon, allspice, and vanilla. Set aside to cool
In a large bowl, whisk the flours, baking powder, and coconut.
Using a large wooden spoon (or your clean hands), mix in the shredded carrot and mashed banana until thoroughly incorporated. Add to the dry ingredients and stir to combine
Using an electric mixer, beat the egg whites until soft peaks form (~ 3-4 minutes)
Fold them into the flour and carrot mix and add the spice-infused butter and stir until smooth.
Spoon the batter into the muffin tins, filling each to about three-quarters full.
Bake for 25-30 minutes, or until golden.
In the meantime, make the frosting. Whisk together the cream cheese, honey, and lime juice in a small bowl.
Allow muffins to cool for 15 minutes on a wire rack.
When ready to eat, spoon each muffin with a tablespoon (or more) of the frosting and sprinkle it with chopped hazelnuts.