Chocolate Marble cookies

I rarely bake a large batch of cookies ^^", well because most of the time, I just bake because I want to try the recipe or just want to eat a bit of it.

This time, my niece wanted me to bake for her classmates and teachers, and it meant I needed to bake a lot of something for her. I choose to make cookie, as it's easy and yes, you can make a load of it in no time. Soft cookie was not suitable for a child to pack to school (as it will be crushed easily), and butter cookie is the right answer for me.
But only plain and simple butter cookie was not what I wanted, something cute and full of flavour was more interesting.
So, I baked chocolate marble cookie for her, this recipe gives you 60-65 pieces of cookie (a lot, haha) but you can bake only half batch of the cookie, and keep the unbaked dough fully covered in the freezer for a month. This type of icebox cookie is very convenient, as you can prepare it before time and bake it whenever you want.

Recipe: Chocolate Marble cookies
สูตรภาษาไทย: ช็อกโกแลตมาร์เบิ้ล คุกกี้
日本語のレシピ：チョコレートマーブルクッキー
Youtube: ช็อกโกแลตมาร์เบิ้ล คุกกี้, Chocolate Marble cookies, チョコレートマーブルクッキー

Chocolate Marble cookies

Makes 60-65 pieces

230 g ...................... Unsalted butter (Soft)
1/2 tsp .................... Salt
1/2 tsp .................... Vanilla extract
270 g ...................... Granulated sugar
2 ............................. Eggs
1 ............................. Egg yolk
490 g ...................... All purpose flour
45 g ........................ Cocoa powder
20 g ........................ Corn starch
30 g ........................ Whipping cream

Beat the butter until smooth.
Add the salt, vanilla and sugar, and beat until fully combine and lighter in color.
Add the eggs and egg yolk, and beat until combine.