1.Preheat oven to 180°C (160°C fan-forced). Adjust oven shelf to lowest position, place an oven tray on the shelf.
2.Triple-sift flour into a medium bowl.
3.Process tea leaves and 3/4 cup (165g) of the sugar until leaves are finely chopped. Transfer mixture to a small bowl of an electric mixer, add egg yolks; beat for 5 minutes or until thick and pale. Gradually add juice, oil and half the rind, beating until well combined. Transfer mixture to a large bowl; sift flour over mixture, then fold gently with a whisk until just incorporated.
4.Beat egg whites in a large bowl with an electric mixer until soft peaks form. Add cream of tartar, then gradually add remaining sugar, beating until mixture is thick and glossy. Fold egg white mixture into yolk mixture, in two batches, until just combined. Spoon mixture into an ungreased 25cm angel food cake pan with a removable base; smooth surface.
5.Place cake pan on preheated oven tray; bake for 50 minutes or until a skewer inserted into the centre comes out clean. Place a piece of baking paper, just larger than the pan on work surface. Immediately turn hot pan upside-down on the paper; leave to cool completely in this position.
6.To make earl grey tea syrup; combine tea leaves and the boiling water in a small saucepan; stand for 10 minutes. Add sugar; stir over low heat until sugar dissolves. Bring to the boil. Boil for 5 minutes or until syrup is reduced slightly. Cool. Strain.
7.Carefully run a small knife around the edge of cake and the tube to help release cake from pan (you may also need to run a knife or spatula between the base and the cake). Using a serrated knife, split cake in half horizontally.
8.Beat cream in a small bowl with an electric mixer until soft peaks form; fold in remaining rind. Place the base cake layer on a cake plate or stand; spread with a little more than half the cream. Finish with remaining cake layer and cream. Decorate with flowers; drizzle with syrup.
Variation; for an orange blossom and mint tea syrup cake, omit the french earl grey tea in the cake and instead add 1 tablespoon orange blossom water with the lemon juice in step 3. Omit the earl grey syrup and instead make ‘orange blossom and mint tea syrup’. Serve the cake drizzled with syrup.