- With the rack in the lowest position, preheat the oven to 325°F (170°C).
- In a bowl, whisk together the flour, baking powder and salt.
- In another bowl, beat the egg whites and cream of tartar with an electric mixer until soft peaks form. Gradually add half the sugar (¾ cup/160 g) while beating until stiff peaks form. Set aside.
- In a large bowl, whisk the remaining sugar (¾ cup) with the oil, water, lemon juice and zest and the egg yolks. Stir in the dry ingredients.
- Stir a quarter of the meringue into the batter. With a spatula, gently fold in the remaining meringue. Pour into a 10-inch (25 cm) ungreased angel food cake pan.
- Bake for 1 hour or until a toothpick inserted into the centre of the cake comes out clean. Immediately flip the pan over and let cool upside down for 3 hours. Run a thin knife blade or a large offset spatula around the cake and unmould.
- With a peeler, cut 3 or 4 large zests from half of the lemon. Cut the peel into thin strips.
- In a saucepan, bring the lemon peel, water and sugar to a boil. Let simmer over low heat for 30 minutes or until the zests are tender and the mixture is syrupy. Let cool.
- Meanwhile, in a bowl, combine the strawberries with half the icing sugar (3 tbsp) and half the vanilla. With a grater, remove the zest from the other half of the lemon and add to the strawberries. Toss and let rest for 30 minutes at room temperature. Strain. Keep the strawberry syrup for another use.
- In another bowl, whip the cream with the remaining sugar (3 tbsp) and vanilla until stiff peaks form.
- With a breadknife, cut the cake horizontally into three slices. Spread the whipped cream over the three pieces. Arrange the drained strawberries on the cream. Place the three pieces on top of one another. Decorate with the candied lemon zests.