Preheat oven to 160°C, lightly grease and flour pan the and set aside
In small bowl, sift together the flour, baking powder and salt. Set aside.
In large bowl, beat together butter, sour cream and sugar on medium-high speed until smooth – about 3 minutes. Beat in the eggs one at a time and vanilla extract, beating well after each addition and scraping bowl often.
Stir in the zests and juices, then fold in the flour mixture until just blended.
Divide batter evenly between Bundtlettes cavities.
Bake for 25-30 minutes, until a toothpick inserted comes out clean