Baking - cookies

I love eating cookies!  Chocolate chip ones really.  I have tried a few recipes and still don't feel I have really got it sorted.  This one from All Recipes I did for a second time recently and really love the texture they produce - soft and gooey which is the best.  I don't think the flavour was quite right last time, but I shall certainly try some more times to be sure. I feel there's lots more info on the website that would help me perfect.

Best big, fat, chewy chocolate chip cookies                 

         Ingredients
Serves: 18 

• 250g plain flour
• 1/2 teaspoon bicarbonate of soda
• 1/2 teaspoon salt
• 170g unsalted butter, melted
• 200g dark brown soft sugar

• 100g caster sugar
• 1 tablespoon vanilla extract
• 1 egg
• 1 egg yolk
• 325g chocolate chips

         Method
Prep:10min  ›  Cook:15min  ›  Ready in:25min 

1. Preheat the oven to 170 C / Gas mark 3. Grease baking trays or line with parchment.
2. Sift together the flour, bicarb and salt; set aside.
3. In a medium bowl, cream together the melted butter, brown sugar and caster sugar until well blended. Beat in the vanilla, egg and egg yolk until light and creamy. Mix in the sifted ingredients until just blended. Stir in the chocolate chips by hand using a wooden spoon. Drop cookie dough onto the prepared baking trays, with each cookie around 4 tablespoons of dough (for smaller cookies, drop 1 rounded tablespoonful and adjust baking time as necessary). Do not flatten the dough. Cookies should be about 8cm apart.
4. Bake for 15 to 17 minutes in the preheated oven, or until the edges are lightly toasted. Cool on baking trays for a few minutes before transferring to wire racks to cool completely.