Adapted from a basic vanilla tea cake recipe for Martha Stewart tea cake pan. The inspiration for the flavors was a drink Starbucks used to sell that was a green tea frapuccino with blackberry topping. —Suzie Sova
To make the icing: In a small bowl combine the preserves and water until smooth. Add sugar and whisk to combine. Add more sugar or water as necessary to reach a fluid consistency but thick enough to coat the back of a teaspoon. If the icing runs off the spoon too quickly it is too thin; add more sugar as needed.
Preheat oven to 375° F. Coat tea cake pan with nonstick spray. Melt butter and set aside to cool.
In a small bowl whisk together flour, and green tea; set aside.
Beat eggs, salt, and sugar with a mixer on medium speed, until pale yellow and very thick about 8 minutes. Stir in vanilla. Fold in flour mixture rapidly but gently. Fold in butter without allowing butter to settle to the bottom of the bowl. Quickly spoon mixture into the pan, until batter is just below the rim.
Bake until cakes spring back when touched lightly; about 11-13 minutes. Invert pan onto wire rack and flip out so cakes are facing up. Spoon glaze on cakes while still warm. Let cool and serve.