Using the whisk attachment of a stand mixer, cream the butter and sugar together on medium speed until well combined. Add egg and mix until combined. Last, mix in oil, milk and vanilla.
In a separate bowl, combine the yam powder, flour, baking powder, baking soda, and salt.
Add flour mixture to egg mixture and beat until integrated.
Place paper baking cups into muffin pans and spoon batter into cups until 2/3 full. Bake at 350 degrees Fahrenheit for 25-30 minutes until a toothpick inserted into the middle comes out clean. Remove cupcakes from pan and let cool on a wire rack for 1 hour. Frost cupcakes with Macapuno Frosting.