Kue Custard Tiga Lapis Ajaib (Dari Satu Adonan)

Instructions

1. Preheat oven to 325F/160C (standard oven / fan forced or convection)
2. Butter a 8" x 8" / 20cm x 20cm square cake tin (Note 4).
3. Beat egg whites with a mixer until stiff peaks form. Set aside.
4. Place the egg yolks and sugar in a bowl and beat until it turns pale yellow - about 1 minute.
5. Add the vanilla extract and butter and beat until well incorporated - about 30 seconds to 1 minute.
6. Add the flour and beat until just combined.
7. Pour the milk in slowly while beating, and beat until well combined (or if using a hand held mixer, add 1/4 milk at a time, beating in between).
8. Use a spatula to fold in the egg whites in the batter, one third at a time, until just incorporated. You don't want to knock the air out of the egg whites. Don't worry if there are a few egg white lumps in the batter. The batter should be very thin, almost like a thick pouring cream.
9. Pour the batter into the prepared cake tin.
10. Bake until the top is golden brown and the cake does not "jiggle" when you gently shake the tin - around 40 to 50 minutes. Check the cake at 30 minutes - if the top is already golden brown but the cake is not yet set (i.e. it jiggles), cover loosely with foil and return to the oven, 10 minutes at a time, until set.
11. Allow to cool in the tin for 10 minutes, then turn out onto a cooling rack.(Note 3) Cool completely before serving.
12. Cut into squares - I cut it into 12 in the photo, but 9 is more realistic serving size portions.
13. Dust with icing sugar just before serving.
14. Serve with a side of whipped cream and strawberries, if using.