In a large bowl sift together the flour, salt & carbonate powder.
In another large bowl mix together both sugars & butter until it is light a fluffy, then mix in the egg & vanilla.
Gradually add in the flour mixture into the sugar & butter mixture, then add in the chocolate chips - reserve some of the chips to the side.
On an ungreased cookie sheet (or cover sheet with baking paper) drop 1 tablespoonful of the cookie dough on the sheet, about 2 inches apart. Spinkle a few chocolate chips over the top of each cookie drop.
Bake for 8 to 10 mins or just until light golden brown.
Let sit for at least 1 minute before removing from the cookie sheet. Remove and cool on racks.