Grease or line 9 cupcake moulds and preheat the oven to 175 C.
Spread the pecans out on un-greased baking tray and bake for 5 minutes, or until they smell toasty and fragrant. Set aside to cool, then chop them coarsely. Mash the banana well (about 1/4 cup after mashing) and set aside as well.
If you're using pre-crushed tinned pineapple, proceed with the next step. If using tinned pineapple slices, first blend them into a puree-like texture in a blender or small food processor.
Now make the batter. In a mixing bowl, whisk the oil and sugar till well-blended. Then add the egg and vanilla and beat again till thoroughly combined. I did this by hand with a balloon whisk but you can use a hand mixer too.
Add the banana, crushed pineapple and coconut and mix well. Sift in the flour, baking soda and cinnamon. Fold to combine into a thick batter, then stir in the chopped toasted pecans (reserve about 2 tablespoons of the pecans to decorate the cupcakes later.)
Divide the batter equally into the cupcake moulds and bake for 15 to 20 minutes until a toothpick poked in the center comes out clean. Let the cupcakes cool completely at room temperature.
While the cupcakes are cooling, make the frosting. Beat the butter and cream together with a hand mixer on medium speed until smooth and creamy. Add the vanilla and sift in the icing sugar. Beat again to combine into a light and fluffy frosting. Refrigerate for 10 to 15 minutes.
Spread the frosting on top of the cupcakes (or use a piping bag if you prefer), decorate with the reserved pecans and pineapple pieces if desired. Dig in! Store the cupcakes in the refrigerator for 4 to 5 days, allowing them to sit at room temperature for about 30 minutes so the frosting softens a little. You can also freeze cupcakes. Happy baking!