Prepare a muffin tin with muffin cups or brush generously with soft butter and pre-heat the oven to 375 degrees F.
In a large mixing bowl, stir together the flour, sugar, baking powder, baking soda, salt, cinnamon, and nutmeg and whisk to combine. In a separate bowl, whisk together the oil, eggs yogurt, and mashed bananas.
Make a well in the center of the dry mix in the large bowl, add the egg mixture and whisk just until blended. Fold in the raisins, if using. Divide the batter among the prepared muffin cups.
Bake for about 24 minutes, or until the muffins spring back when pressed gently with your finger. Cool for about 15 minutes and gently invert muffins onto a wire rack. If sticking occurs, gently run a small offset spatula along the inside edge of the muffin tin to loosen.
Photography by Nathaniel Crawford - Terminatetor Kitchen