Gather all ingredients. Preheat the oven to 325 degrees F (165 degrees C).
Beat egg whites and cream of tartar in the bowl of a stand mixer fitted with the whisk attachment until stiff peaks form; set aside.
Beat egg yolks and sugar together in a separate bowl until sugar dissolves.
Whisk water and pandan paste together in a separate bowl until smooth; stir into egg yolk mixture. Stir in oil; fold in flour.
Gently fold egg yolk-pandan mixture into egg whites with a spatula; pour into a 9-inch chiffon cake mold.
Bake in the preheated oven until a toothpick inserted into center comes out clean, 45 to 50 minutes.
Cool cake in the pan, inverted onto a wire rack. Run a sharp knife around edges to loosen cooled cake from the mold, invert carefully onto a serving plate.
