Almond Butter Sponge Cake

A Facebook member posted this sponge cake with good reviews.  I have never bake a sponge cake and I have all the required ingredients for this cake.  This is indeed a keeper.

Ingredients: (7″ Square /8″ Round Pan)

(A)
6 egg yolks (60g with shell)
40g caster sugar
200 melted butter, cooled
2tbsp vanilla extract (I used 1.5 tbsp.)

(B)
6 egg whites
120g caster sugar
100g almond flour (aka ground almond)
1/4 tsp salt (I omitted)

Method:

1. Whisk egg yolks and sugar from (A) till fluffy.  Add in vanilla extract and set aside.
2. Whisk (B) till firm peaks.
3. Sieve flour into mixture (A) and mix.  Add in almond flour.  Batter will be sticky at this stage.  Add 1/3 meringue to loosen the gluten.  Continue to fold in the remaining meringue, 1/3 at a time.
4. Pour into lined tin tapping the bowl as you pour the batter to release trapped air.  Shake the tin to level the batter.
5. Bake at 160 degree C at lowest rack or until golden brown.