Preheat oven to 350°F and lightly grease donut pan.
Whisk together sweet potatoes, pineapple, and sugars until smooth.
Add oil, eggs, and vanilla; whisk until creamy.
Combine flour, baking powder, baking soda, cinnamon, nutmeg, and salt in another bowl.
Fold dry ingredients into wet until just combined.
Spoon or pipe batter into donut rings, filling each about ¾ full.
Bake 15–18 minutes until golden and springy.
Cool for 5 minutes, then flip pineapple side up before serving.
