Apple Soft Pound Cake

butter (room temperature) (7.93oz)

caster sugar (3/4 cup)

large eggs (about 210g) - separated

vanilla extract

plain flour/cake flour (1.5 cup)

corn flour (1/4 cup) - corn starch

baking powder (1 tsp)

green apple, peeled and cubed and mix with 1½ tbsp lemon juice (about 2 cups)

Lemon zest from 1 large lemon