Calculating for homemade recipes

I have a cookie recipe that I enjoy a lot and it would help me eat my syns each day and have a treat. In calculating the syns for the recipe, do I calculate the syns for each item, add them together, then divide by the number of servings?

Any idea on the syns for chocolate chips - I use the dark chocolate ones.

Are spices, salt and vanilla syn free?

Also the syns for canned pumpkin (not the pumpkin pie filling)? My US list has cooked raw pumpkin as free for both original (red) and green.

Thanks for your help.

Christy