Preheat your oven to 180 celsius.
Mix together all dry ingredients.
Melt butter and let it cool little before you add other ingredients.
Add sugar to butter and mix together gently.
Add the egg and mix well. Add vinegar and vanilla extract, again mix well but gently don´t over mix.
Add flour mixture to butter mixture and fold together. Add chocolate chips.
Scoop cookie dough with ice cream scoop. It should make about 12-15 cookies. If you don´t have ice cream scoop just make 12-15 cookie dough balls with your hands. Just don´t make them too tight.
Place cookie dough balls on baking tray over baking paper. Let there be about 7cm gap between cookie dough balls. These cookies will spread a lot.
Press couple chocolate chips over cookie dough balls.
Bake cookies 12-15 minutes until the edges are golden. Center of the cookies might still seem under cooked but that´s just how we want them.
After you take cookies out of the oven let them stay on baking tray so they will keep cooking. Let cookies cool completely preferably over night.