For the cupcakes
Preheat oven to 350 °F and line mini muffin tins with paper liners
Sift flours, baking powder and salt and set aside. Whisk milk, oil and vanilla bean paste together and set aside.
Whip egg whites with 6 tbsp of sugar until they hold a soft peak when beaters are lifted. In a separate bowl, whip egg yolks with remaining 6 tbsp of sugar until doubled in volume and a pale, butter colour. Fold whipped whites into yolk mixture. Fold flour into whipped eggs in two additions. Stir a spoonful of batter into milk mixture then add all back to batter, folding quickly to incorporate. Pipe or spoon batter into prepared muffin cups, 3/4-full. Bake for 13 to 15 minutes, until cupcake springs back when touched. Let cool.
For the Icing
Beat cream cheese and butter until fluffy and smooth. On low speed, add icing sugar, 1 cup at a time, until blended. Beat in vanilla bean paste and add milk, 1 tbsp at a time until desired consistency is achieved. Ice cupcakes as desired.