Beat the eggs and sugar with a mixer in a bowl. Add the sunflower oil and the tea you brewed and continue beating. Sift the flour, cocoa, baking powder and vanilla and add them to the mixture. Stir carefully with a wooden spoon or a spatula. Grease a loaf cake tin and spread the beaten mixture into it. Bake for 45-50 minutes in an oven preheated to 180 degrees. Take the baked cake out of the oven and let it cool. You can spread chocolate ganache over the cooled cake. Enjoy your meal!