Step 1

Preheat oven to 180C / 350F (standard) or 160C/320F (fan / convection). Place oven shelf in the middle of the oven.

Step 2

Line 2 trays with baking / parchment paper.

Step 3

Whisk the flour, salt and baking soda in a bowl.

Step 4

Place the butter in a large heatproof bowl. Microwave until the butter is almost fully melted (25 sec for room temp butter, 40 sec for fridge cold butter on high).

Step 5

Whisk to finish melting the butter. (Note 2)

Step 6

Add brown and white sugar, whisk energetically for 15 seconds.

Step 7

Add egg, yolk and vanilla, whisk well for 15 seconds.

Step 8

Add flour mixture and mix until flour is almost fully incorporated.

Step 9

Add 1 cup chocolate chips, stir to disperse and flour is fully incorporated. Batter will be quite loose.

Step 10

Stand for 5 minutes for batter to firm up a bit so it is scoop-able into mounds. (Note 3)

Step 11

LARGE COOKIES: Scoop up a level ice cream scoop / 3 tbsp / 1/4 cup (Note and place on baking trays 5cm / 2" apart - 13 balls. Top with remaining choc chips (these remain on surface once baked = prettier).

Step 12

SMALL COOKIES (26 - 30): Scoop up 1.5 tbsp (heaped tbsp measure) OR 1/2 an ice cream scoop (this works well). Place on baking trays 4cm / 1.75" apart, top with choc chops.

Step 13

Bake 1 tray at a time. LARGE COOKIES: Bake for 8 minutes, then rotate the tray and bake for 3 minutes (11 minutes in total). SMALL COOKIES: Bake 6 minutes, turn then bake 3 minutes (9 min total). The cookies should be just golden on the edges and pale golden on top. They will be slightly puffed up.

Step 14

Cool on the tray - they finish cooking. They will lose the puffiness while resting. Dig in and get your cookie fix!