Preheat your oven to 350°F (175°C) and line a 9x13 inch baking pan with parchment paper.

Take three jasmine tea bags and steep them in a cup of hot water for about 10 minutes. Once done, remove the tea bags and let the liquid cool.

In a separate bowl, combine the cake flour and baking powder. Add the tea leaves from the remaining two jasmine tea bags to the flour mixture.

Separate the egg whites from the yolks, beat the egg whites with cream of tartar until frothy, then gradually add in granulated sugar until stiff peaks form.

In another bowl, whisk the egg yolks and remaining sugar until creamy. Mix in the cooled jasmine tea, light oil, and vanilla extract. Sift in the flour mixture slowly.

Gently fold the whipped egg whites into the yolk mixture using a spatula until well combined.

Pour the batter into the prepared pan and bake for 25-27 minutes, or until a toothpick comes out clean. Let the cake cool completely in the pan.

Use a 6-inch ring to cut out layers from the cake, keeping rounds intact or making smaller pieces.

In a chilled mixing bowl, whip the cream with powdered sugar and a splash of vanilla extract until firm peaks form.

Assemble your cake with layers of cake, whipped cream, and quartered green grapes, finishing with whipped cream on top.

Cover and chill the cake in the refrigerator for at least 4 hours to set.

Before serving, decorate the top with additional whipped cream and halved grapes. Serve chilled.