Preheat oven to 300 F and grease and flour 6 mini bundt tins. Cream together butter and sugar until pale and fluffy. Stir in honey and tangerine zest. Add eggs one at a time, mixing well after each addition. In a separate bowl, combine mayonnaise, tangerine juice, grated ginger and vanilla. Stir into egg mixture. Sift flours, baking powder, ground ginger, green tea powder and salt and stir in with poppy seeds, being careful not to overmix. Spoon evenly into prepared pans and bake for 25 to 35 minutes, until a tester inserted in the centre of a cake comes out clean. Allow to cool for 15 minutes, then run a palette knife around edges of cakes to loosen and remove from pan. Allow to cool completely.